Side-loading carriage for use in surgical guide

ABSTRACT

Devices, systems, and methods are provided for ligament repair procedures, and can be used to establish a location and trajectory for forming a bone tunnel in bone. One exemplary embodiment of a surgical guide for using in a ligament repair procedure includes a guide arm and a carriage that can be selectively locked along the guide arm to define an angle of the bone tunnel. The guide arm also defines a location of a distal end of the bone tunnel. In some embodiments the carriage is configured to have a bullet side-loaded into it, and the bullet can be used to define a location of a proximal end of the bone tunnel. The present disclosure also provides for a gage that limits the distance a drill pin that drills the bone tunnel can travel. A variety of other, devices, systems, and methods are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.14/503,193, filed Sep. 30, 2014, and entitled “Side-Loading Carriage forUse in Surgical Guide,” which is hereby incorporated by reference in itsentirety.

FIELD

The present disclosure relates to systems, devices, and methods forforming a tunnel or bore in bone, and more particularly relates to aligament (e.g., ACL and PCL) modular guide, a drill pin depth gage, andcomponents used in conjunction with the guide and gage.

BACKGROUND

Ligaments are tough bands of tissue that serve to connect the articularextremities of bones or to support or retain organs in place within thebody. Ligaments are typically composed of coarse bundles of dense whitefibrous tissue which are disposed in a parallel or closely interlacedmanner, with the fibrous tissue being pliant and flexible, but notsignificantly extensible. Two well-known ligaments are the anterior andposterior cruciate ligaments (i.e., the ACL and PCL), which extendbetween the proximal end of the tibia and the distal end of the femur.The ACL and PCL cooperate, together with other ligaments and softtissue, to provide both static and dynamic stability to the knee.

Ligaments such as the ACL and PCL can tear or rupture for a variety ofreasons, including as a result of accidents or overexertion. In fact,the injury of an ACL or PCL is a common sports-related injury.Consequently, various surgical devices and procedures have beendeveloped for reconstructing ACLs and PCLs to restore normal function tothe knee. In many instances, the ACL or PCL may be reconstructed byreplacing the ruptured ligament with a graft ligament. Moreparticularly, with such procedures, bone tunnels are typically formed inthe proximal end of the tibia and the distal end of the femur, with oneend of the graft ligament being positioned in the femoral tunnel and theother end of the graft ligament being positioned in the tibial tunnel.The two ends of the graft ligament are anchored in place in various waysknown in the art so that the graft ligament extends between the femurand the tibia in substantially the same way, and with substantially thesame function, as the original ligament. This graft ligament thencooperates with the surrounding anatomical structures so as to restorenormal function to the knee.

Modular guides can be used to help form the bone tunnels in an ACL orPCL graft ligament procedure. The guides help to define a location ofthe tunnel to be formed in bone and subsequently direct one or moretools for drilling through the bone at the desired tunnel location. Oneembodiment of a modular guide 10 is provided for in FIGS. 1A and 1B. Asshown, the guide 10 includes a frame 12 for receiving both atranslatable arm 14 and a bullet 16. The location at which the frame 12receives the bullet 16 is stationary, while the arm 14 is configured totranslate through the frame 12 to set an angle or trajectory of one ormore desired bone tunnels, as shown a tibial tunnel 6 and a femoraltunnel 8. As shown, a distal tip 16 d of the bullet 16 can be positionedat a desired location for a proximal end 6 p, 8 p of the bone tunnel 6,8 and an end 14 d of the arm 14 can be positioned at a desired locationof a distal end 6 d, 8 d of the same bone tunnel 6, 8. A thumb screw 18can be provided to allow a user to lock the location of the translatablearm 14 with respect to the frame 12, thereby setting the angle ortrajectory of the desired bone tunnel 6, 8.

Guides of the nature illustrated in FIGS. 1A and 1B can suffer from anumber of different problems. For example, a surgeon may end up missingthe predetermined target with a drill pin, which is sometimes referredto as divergence. Divergence can occur for a host of reasons. In someinstances, divergence occurs because the arm of the modular guide is notsecurely locked in position with respect to the frame, and thus theintended angle or trajectory moves, causing the drill to miss itsintended mark. Alternatively, a surgeon may accidentally disengage thethumb screw because his or her hand is holding the frame near thatlocation in use. Still further, if a change in the intended angle ortrajectory needs to be made by the surgeon intra-operatively (as opposedto pre-setting the trajectory), the surgeon may accidentally shift thedistal tip of the bullet and/or the end of the arm when adjusting his orher grip to loosen and then tighten the thumb screw. Having the portionof the device that the user operates to define the trajectory coincidewith the portion of the device gripped by the user during operation ofthe device creates and compounds these problems.

In some instances, the tunnel is formed using a retrograde reamer 19such that after a pilot tunnel is drilled, the retrograde reamer 19 isoperated from the distal end 6 d, 8 d to the proximal end 6 p, 8 p ofthe tunnel 6, 8 to enlarge the tunnel. Such a procedure typicallyinvolves drilling a pilot hole using the guide and bullet and thendisassociating the guide from the reamer before operating the reamer sothat the guide does not constrict the surgeon operating the reamer. Inorder to disassociate the guide from the reamer though, the bullet mustfirst be removed by sliding it up the shaft of the retrograde reamer.Then the guide is removed and the bullet can be slid back down the shaftof the reamer so that the bullet can assist with keeping the desiredtrajectory of the reamer during cutting. Because of this set-up, theshaft of the retrograde reamer must be longer than would be necessaryjust for cutting because extra length is needed to allow the bullet tobe slid far enough up the reamer 19 that the distal tip 16 d of thebullet 16 is proximal of the frame 12 while still keeping the reamer atthe distal end of the bone tunnel. This, in turn, allows the frame 12 tobe disassociated from the bullet 16 so that the frame 12 and arm 14 canbe removed from the surgical site. Of course, the extra length of thereamer can increase the likelihood of divergence due to flexing of thelong retrograde reamer shaft. When divergence does occur, the surgeonwill typically have to re-drill or make further adjustments to theimplant, related components, and/or the surgical procedure to accountfor the incorrectly located bone tunnel. Such adjustments are typicallyless desirable than correctly drilling the tunnel to start.

Guides of the nature illustrated in FIGS. 1A and 1B are furtherdeficient because they are not universal. A right-handed surgeon and aleft-handed surgeon typically need different guides so that controlssuch as the thumb screw are appropriately located for the variousprocedures with which the guides can be used. Likewise, theconfiguration of existing guides do not lend themselves to be used fromany side of either knee with either the right hand or left hand withoutmodifying the device or having the surgeon contort his or her body touse the guide.

A further problem that plagues surgeons during ACL and PCLreconstruction procedures is over-drilling, i.e., extending the dill pinfurther distally than the desired distal end of the bone tunnel. Ineither procedure, but particularly during PCL repairs, it can be crucialto insure that the drill pin is not over-drilled to prevent undesirabledamage to the surrounding tissue and the like. For example, during a PCLrepair, over-drilling can risk damage to the femoral articular cartilageand/or can puncture the neurovascular structure in the posterior portionof the knee.

Accordingly, there remains a need for improved systems, devices, andmethods for use in performing ligament repairs that decrease the risk ofdivergence and/or over-drilling and improve the ability for suchsystems, devices, and methods to be used universally, i.e., such thatthe same systems, devices, and methods can be used with either hand, oneither knee to form tibial and femoral tunnels, while sitting orstanding in the same location.

SUMMARY

Devices, systems, and methods are generally provided for ligament repairprocedures such as procedures performed in ligament (e.g., ACL and PCL)reconstruction surgeries. The devices and systems provided for relate tosurgical guides used to establish a location and trajectory for forminga bone tunnel in bone. The surgical guides provided for afford a numberof advantages, including limiting the risk of divergence to improve theaccuracy of bone tunnel formation. The disclosures herein also providefor various embodiments of carriages, which can be a component of asurgical guide and can be used to receive a bullet for use in variousrepair procedures. The carriages provided for also afford a number ofadvantages, including allowing for shorter drilling tools, whichdecreases the risk of divergence. They also allow for the portion of thedevice involved in setting the angle or trajectory of the bone tunnelformation to be separate from the portion of the device gripped by theuser during operation. Still further, the devices and systems providedfor herein include a drill pin depth gage that can be used to help set alength of a drill pin to prevent the pin from traveling further thandesired when drilling a bone tunnel in bone. This, in turn, decreases arisk of damaging surrounding tissue, nerves, and other aspects of thebody.

In one exemplary embodiment, a surgical instrument includes a guide armand a carriage. The guide arm has a first portion that is configured todefine an angle at which a bore is to be drilled into bone and a secondportion that is configured to define a location of a distal end of thebore to be drilled into bone. An angle extending between the first andsecond portions can be approximately 110 degrees or less. The carriagecan be disposed on the first portion of the guide arm. The carriage canhave a length that is greater than a width or a thickness thereof, andthe length of the carriage can extend substantially transverse to alength of the first portion of the guide arm. The carriage can beconfigured to translate along a length of the first portion. Further,the carriage can be configured to be selectively located at differentlocations along the length of the first portion to set the angle ortrajectory at which a bore is to be drilled into bone.

The carriage can include a bullet-receiving opening formed therein thatis configured to receive a bullet. In some embodiments, the surgicalinstrument can include a bullet. The bullet can be configured to beremovably coupled to the carriage and, when coupled to the carriage, thebullet can be configured to define a location of a proximal end of thebore to be drilled into bone. The bullet can be tapered towards itsdistal end. It can also be cannulated. A proximal face of the bullet canhave a width that is greater than a diameter of a distal portion of thebullet, and the proximal face can be concave to facilitate insertion oftools into a bore extending through the bullet.

The first portion of the guide arm can include opposed first and secondflat surfaces and first and second sidewalls that extend between thefirst and second flat surfaces. The surface areas of the flat surfacescan be substantially larger than the surface areas of the sidewalls. Thecarriage can include first and second facial surfaces, as well as firstand second side surfaces that extend between the first and second facialsurfaces. The first and second flat surfaces of the guide arm can extendsubstantially parallel to the first and second facial surfaces, with thefirst facial surface of the carriage facing away from the first flatsurface of the first portion of the guide arm. The bullet-receivingopening can be formed in the first facial surface of the carriage. Thecarriage can be configured such that a bullet received by thebullet-receiving opening is held at an angle with respect to the secondflat surface such that a drill pin extending through a bullet disposedin the bullet-receiving opening is configured to engage a distal end ofthe second portion of the guide arm that defines the location of thedistal end of the bore to be drilled into bone. The second portion ofthe guide arm can include a distal tip disposed at a terminal end of thesecond guide arm. The distal tip can be configured to engage bone at anintended location of the distal end of the bore to be drilled into bone.

In some embodiments, the first portion of the guide arm is not movablewith respect to the second portion of the guide arm when the first andsecond arms are coupled together. The first portion of the guide arm caninclude a plurality of slots formed therein, with each slot beingindicative of an intended angle at which the bore is to be drilled intobone. Each slot of the plurality of slots can be disposed at locationssuch that the intended angles are at intervals of five degrees along thefirst portion. The carriage can include a passive locking mechanism thatis configured to passively engage a slot of the plurality of slots toset the angle at which the bore is to be drilled into bone. The passivelocking mechanism can include a selectively deployable key having aconfiguration that is complementary to the plurality of slots such thatwhen the selectively deployable key is disposed in a slot, the locationof the carriage is fixed with respect to the first portion of the guidearm. The passive locking mechanism can also include a button configuredto disengage the selectively deployable key from a slot of the pluralityof slots to allow the carriage to translate a long a length of the firstportion. The selectively deployable key can be disposed on a bar thatextends between a proximal end and a distal end of the carriage. The barcan have an opening formed therein that allows indicia associated withthe plurality of slots to be viewable.

In another exemplary embodiment, a surgical guide for use in conjunctionwith drilling a bore in bone includes a first arcuate arm, a second arm,and a bullet configured to be removably associated with the firstarcuate arm. The first arcuate arm can have a first end, a second end,and an intermediate portion extending therebetween, with theintermediate portion having indicia formed on it to indicate an intendedangle at which a bore is to be drilled into bone. The second arm canalso have a first end, a second end, and an intermediate portionextending therebetween. The first end of the second arm can be directlyconnected to the second end of the first arm to form a unitaryconstruction of the guide such that the second arm is substantiallystationary with respect to the first arm, and an angle extending betweenthe first and second arms is approximately 110 degrees or less. Theremovable association between the bullet and the first arm can be suchthat a location of the bullet with respect to the indicia formed on thearm reflects an intended angle at which a distal tip of the bullet is toform with the bone in which the bore is to be drilled, which in turndefines the intended angle or trajectory of the bore to be drilled intothe bone.

The first arm can include opposed first and second flat surfaces andfirst and second sidewalls that extend between the first and second flatsurfaces. The surface areas of the flat surfaces can be substantiallylarger than the surface areas of the sidewalls. In some embodiments, theindicia can also include a plurality of slots formed on a surface of thefirst arcuate arm. Each slot of the plurality of slots can be disposedat locations such that the intended angles are at intervals of fivedegrees along the first arm. The second end of the second arm caninclude a distal tip that is configured to engage bone at an intendedlocation of a distal end of the bore to be drilled into the bone.

The bullet can be tapered towards its distal end. It can also becannulated. A proximal face of the bullet can have a width that isgreater than a diameter of a distal portion of the bullet, and theproximal face can be concave to facilitate insertion of tools into abore extending through the bullet.

In some embodiments, the guide can include a carriage that is configuredto receive the bullet. The carriage can translate along a length of thefirst arm, and can be selectively locked with respect to the indicia toset the intended angle formed by the distal tip of the bullet with thebone in which the bore is to be drilled. This, in turn, sets theintended angle or trajectory of the bore to be drilled in the bone. Thecarriage can include first and second opposed facial surfaces and firstand second side surfaces extending between the first and second facialsurfaces. The first facial surface of the carriage can face away fromthe first arcuate arm. The carriage can be configured such that thebullet received by the carriage is held at an angle with respect to thefirst arcuate arm such that a distal tip of a drill pin extendingthrough the bullet is configured to engage a distal tip of the secondarm. In some embodiments, the carriage can include a bullet-receivingopening that is configured to receive the bullet.

In some embodiments in which the indicia include a plurality of slotsformed in a surface of the first arcuate arm, the carriage can include apassive locking mechanism configured to passively engage a slot of theplurality of slots to set the intended angle or trajectory of the boreto be drilled into bone. The passive locking mechanism can include aselectively deployable key having a configuration that is complementaryto the plurality of slots such that when the selectively deployable keyis disposed in a slot, the location of the carriage is fixed withrespect to the first arm. The passive locking mechanism can also includea button configured to disengage the selectively deployable key from aslot of the plurality of slots to allow the carriage to translate a longa length of the first arm. The selectively deployable key can bedisposed on a bar that extends between a proximal end and a distal endof the carriage. The bar can have an opening formed therein that allowsindicia associated with the plurality of slots to be viewable.

An exemplary method for drilling a bore in bone can include positioninga second end of a second arm of a surgical guide adjacent to a desiredlocation for a distal end of a bore to be drilled in bone, andpositioning a first end of a first arm of the surgical guide proximateto an opposed side of the bone, the opposed side being the location atwhich a proximal end of the bore to be drilled in bone is to be located.The first arm can be disposed in a hand of a user such that noadditional component of the surgical guide is disposed therebetween. Themethod can further include adjusting the surgical guide to set an anglebetween a distal tip of a bullet that is to be associated with thesurgical guide and the bone to be drilled. This adjustment occurswithout moving the first arm relative to the second arm, and the angleis formed at the location at which the proximal end of the bore is to bedrilled. The method can further include disposing a drill pin in athrough-bore of the bullet, and operating the drill pin to drill a holefrom the location at which the distal tip of the bullet forms an anglewith the bone to the location at which the second end of the second armis located.

In some embodiments, adjusting the surgical guide to set an anglebetween a distal tip of a bullet that is to be associated with thesurgical guide and the bone to be drilled includes locking a location ofa carriage on the first arm. The carriage can be configured to receivethe bullet and can also be configured to translate a length of the firstarm to establish different angles at which the angle between the distaltip of the bullet and the bone can be set.

The first arm can include a plurality of slots formed therein, and thecarriage can include a passively engaging male member that is configuredto engage a slot of the plurality of slots as part of the step oflocking a location of the carriage on the first arm. In suchembodiments, the method can include actively disengaging the male memberfrom the slot, moving the carriage along the first arm, and allowing themale member to engage a slot of the plurality of slots to lock thelocation of the carriage on the first arm. Actively disengaging the malemember from the slot can include pushing a button associated with thecarriage and subsequently releasing the button prior to allowing themale member to engage a slot of the plurality of slots.

The method can also include a step of coupling the drill pin to a chuckof a surgical drill such that a distal tip of the drill pin extends nofurther distally than the second end of the second arm located adjacentto the distal end of the bore.

In one exemplary embodiment of a carriage for use with a surgical guide,the carriage includes a housing having a proximal end, a distal endopposed to the proximal end, opposed first and second side surfaces thatextend between the proximal and distal ends, and opposed first andsecond facial surfaces that extend between the proximal and distal endsand the first and second side surfaces. A guide-receiving opening canextend through the housing and through the first and second sidesurfaces. The guide-receiving opening can be configured to receive anarm of a surgical guide along which the carriage is configured totranslate. A bullet-receiving opening can extend through the housing andthrough the proximal and distal ends. The bullet-receiving opening canbe configured to be open towards the first facial surface to receive abullet for use with a surgical guide associated with the carriage. Theguide-receiving opening and the bullet-receiving opening can extend indifferent planes, and can be substantially transverse to each other.

In some embodiments, the bullet-receiving opening can be configured toreceive a bullet by passing the bullet from an outside environment,across a plane extending substantially through the first facial surface,and into the bullet-receiving opening. Further, the bullet-receivingopening can be configured to hold a received bullet in a locked positionin which the received bullet cannot translate between the two sidesurfaces or between the two facial surfaces. A rotatable receiver can bedisposed in the housing. The rotatable receiver can extend from theproximal end to the distal end, with the bullet-receiving opening beingdisposed in the rotatable receiver. The rotatable receiver can berotatable between a receiving position in which the bullet-receivingopening is open towards the first facial surface to receive a bullet foruse with a surgical guide associated with the carriage, and a lockingposition in which the bullet-receiving opening is rotated towards thesecond facial surface and the bullet is in the locked position.

A bullet engagement protrusion can extend through the rotatable receiverand can be configured to engage an engagement slot of a bullet disposedin the bullet-receiving opening to maintain the bullet in the lockedposition. A release button can be provided to disengage the bulletengagement protrusion from an engagement slot of a bullet disposed inthe bullet-receiving opening to remove the bullet from the lockedposition. The release button can be in communication with the bulletengagement protrusion to provide the disengagement. In some embodiments,the carriage also includes a bullet configured to be removably disposedin the bullet-receiving opening.

A receiving ramp can be disposed within the housing. The receiving rampcan be configured to receive the rotatable receiver and maintain it inthe locking position to maintain a bullet disposed in thebullet-receiving opening in the locked position. Further, in someembodiments the rotatable receiver can include opposed indents formed inits proximal end. A surface of the first indent can be configured toengage the ramp when the rotatable receiver is in the locking position,and a surface of the second indent can be configured to engage the rampwhen the rotatable receiver is in the receiving position.

The second facial surface can include a top portion and a bottom portionwith an opening extending therebetween, and can also include a portionof a surgical guide engagement feature disposed in the opening thatextends between the top and bottom portions to bound the guide-receivingopening. The surgical guide engagement feature can be configured totranslate longitudinally between the proximal and distal ends toselectively lock a location of the carriage with respect to a surgicalguide. The surgical guide engagement feature can include a passivelyengaging male member that is configured to engage a slot disposed on anarm of a surgical guide.

In another exemplary embodiment of a carriage for use with a surgicalguide, the carriage includes a housing and a bullet receiver rotatablycoupled to the housing. The housing can have a guide-receiving openingformed therein, with the guide-receiving opening being configured toreceive an arm of a surgical guide along which the carriage isconfigured to translate. The bullet receiver can have a bullet-receivingopening formed in it to receive a bullet for use with a surgical guideassociated with the carriage. The bullet receiver can rotate between areceiving position in which the bullet receiving opening is open towardsan environment outside of the housing to receive a bullet for use with asurgical guide associated with the carriage, and a locking position inwhich the bullet-receiving opening is rotated towards the housing toplace a bullet disposed therein in a locked position in which thereceived bullet cannot translate between the two side surfaces orbetween the two facial surfaces of the housing. In the locking position,the bullet can translate distally. The bullet receiver can also have anintermediate position in which the bullet is received in the bulletreceiving opening and the bullet is able to translate freely bothdistally and proximally.

In some embodiments, the carriage can include a bullet engagementprotrusion that extends through the bullet receiver and can beconfigured to engage an engagement slot of a bullet disposed in thebullet-receiving opening to maintain the bullet in the locked position.A release button can be provided to disengage the bullet engagementprotrusion from an engagement slot of a bullet disposed in thebullet-receiving opening to remove the bullet from the locked position.The release button can be in communication with the bullet engagementprotrusion to provide the disengagement. In some embodiments, thecarriage also includes a bullet configured to be removably disposed inthe bullet-receiving opening.

A receiving ramp can be disposed within the housing. The receiving rampcan be configured to receive the bullet receiver and maintain it in thelocking position to maintain a bullet disposed in the bullet-receivingopening in the locked position. Further, in some embodiments the bulletreceiver can include opposed indents formed in its proximal end. Asurface of the first indent can be configured to engage the ramp whenthe bullet receiver is in the locking position, and a surface of thesecond indent can be configured to engage the ramp when the bulletreceiver is in the receiving position.

A surgical guide engagement feature can be provided as part of thecarriage. The surgical guide engagement feature can be configured totranslate longitudinally and thus substantially transverse to an axisextending through the guide-receiving opening to selectively lock alocation of the carriage with respect to a surgical guide. The surgicalguide engagement feature can include a passively engaging male memberthat is configured to engage a slot disposed on an arm of a surgicalguide.

The various embodiments of the carriage provided for can be used inconjunction with a surgical instrument that includes a surgical guidehaving an elongate arm. The elongate arm can be disposed in theguide-receiving opening of the carriage such that the carriage istranslatable along the elongate arm. The carriage can be configured toselectively lock to maintain a location of the carriage with respect tothe elongate arm.

An exemplary surgical method provided for herein includes setting asurgical guide to define a path for a retrograde reamer to drill a borein bone at a surgical site. The path can be set such that a distal tipof a bullet coupled to the surgical guide is located proximate to adesired location for a proximal end of the bore. The method can furtherinclude drilling a pilot hole in the bone along the defined path using adrill pin end of a retrograde reamer. The bullet can then be decoupledfrom the surgical guide, and the surgical guide can be removed from thesurgical site. The process of decoupling the bullet from the surgicalguide can be accomplished without removing the retrograde reamer fromthe bullet. A reamer associated with the drill pin can then be operatedto expand the pilot hole formed in bone by advancing the reamerproximally.

In some embodiments, the step of setting a surgical guide to define apath for a reamer can include positioning a second end of a second armof the surgical guide adjacent to a desired location for a distal end ofa bore to be drilled in bone, and positioning a first end of a first armof the surgical guide proximate to an opposed side of the bone, theopposed side being the location at which a proximal end of the bore tobe drilled in bone is to be located. The step can further includeadjusting the surgical guide to set an angle between the distal tip ofthe bullet and the bone to be drilled, the angle being formed at thelocation at which the proximal end of the bore is to be drilled.

The surgical guide used in the method can have a carriage disposed alongan arm of the guide. The carriage itself can have a housing and abullet-receiving opening, and the bullet can be coupled to the surgicalguide by being disposed in the bullet-receiving opening. In someembodiments, the bullet can be rotated in a first direction within thebullet-receiving opening to set the bullet in a locked position in whichthe bullet cannot translate away from and substantially perpendicular tothe arm of the carriage. Further, the bullet can be decoupled from thesurgical guide by rotating the bullet in a second direction, opposite tothe first direction, such that the bullet is removed from the lockedposition and is able to be moved away from and substantiallyperpendicular to the arm of the carriage. Alternatively, the bullet canbe decoupled from the surgical guide by activating a release buttonassociated with the carriage such that the bullet is removed from thelocked position and is able to be moved away from and substantiallyperpendicular to the arm of the carriage. When the bullet is in thelocked position, it can be configured to translate distally, but notproximally.

In some embodiments the carriage can be configured to translate along alength of the arm to establish different angles at which the anglebetween the distal tip of the bullet and the bone can be set. In suchembodiments, the method can include locking a location of the carriageon the arm of the surgical guide. The arm can include a plurality ofslots formed therein and the carriage can include a passively engagingmale member that is configured to engage a slot of the plurality ofslots as part of the step of locking a location of the carriage on thearm of the surgical guide. In such embodiments, the method can includeactively disengaging the male member from the slot, moving the carriagealong the first arm, and allowing the male member to engage a slot ofthe plurality of slots to lock the location of the carriage on the firstarm. Actively disengaging the male member from the slot can includepushing a button associated with the carriage and subsequently releasingthe button prior to allowing the male member to engage a slot of theplurality of slots.

The method can also include a step of coupling the drill pin to a chuckof a surgical drill such that a distal tip of the drill pin extends nofurther distally than the second end of the second arm located adjacentto the distal end of the bore. A length of the shaft of the reamer canbe approximately equal to a length of the bullet and a length of thebore drilled in bone.

In one exemplary embodiment of a university surgical guide system, thesystem can include a guide arm and a carriage. The guide arm can have afirst portion configured to define a trajectory or angle at which a boreis to be drilled into bone and a second portion configured to define alocation of a distal end of the bore to be drilled into bone. The firstportion can have opposed surfaces thereof, and each of the opposedsurfaces can have formed therein a plurality of slots. Each slot can beindicative of an intended trajectory or angle for the bore to be drilledinto bone. The carriage can be disposed on the first portion of theguide arm, and can be configured to translate along a length of thefirst portion. Further, the carriage can be configured to selectivelylock within a slot of the plurality of slots to set the intendedtrajectory at which the bore is to be drilled into bone.

The carriage can include a bullet-receiving opening that is formed inthe carriage. The bullet-receiving opening can be configured to receivea bullet. In some embodiments, the system can include a bullet. Thebullet can be configured to be removably coupled to the carriage and,when coupled to the carriage, the bullet can be configured to define alocation of a proximal end of the bore to be drilled into bone. In someembodiments, the carriage can be configured such that a bullet receivedby the bullet-receiving opening is held at an angle with respect to thefirst portion of the guide arm such that a distal tip of a drill pinextending through a bullet disposed in the bullet-receiving opening isconfigured to engage a distal end of the second portion of the guide armthat defines the location of the distal end of the bore to be drilledinto bone.

The carriage can include a passive locking mechanism that is configuredto passively engage a slot of the plurality of slots to set thetrajectory or angle at which the bore is to be drilled into bone. Thepassive locking mechanism can include a selectively deployable key thathas a configuration that is complementary to the plurality of slots suchthat when the selectively deployable key is disposed in a slot, thelocation of the carriage is fixed with respect to the first portion ofthe guide arm. In some embodiments the passive locking mechanism caninclude a button configured to disengage the selectively deployable keyfrom a lot of the plurality of slots to allow the carriage to translatealong a length of the first portion.

In some embodiments the first portion of the guide arm is not movablewith respect to the second portion when the first and second portionsare coupled together. A second portion of the guide arm can include adistal tip that is disposed at a terminal end of the second guide arm.The distal tip can be configured to engage bone at an intended locationof the distal end of the bore to be drilled into bone.

In another exemplary embodiment of a universal surgical guide system,the system can include a guide portion and a locking portion. The guideportion can be configured to define a location and a trajectory of abore to be drilled in bone, and further, can be configured to be grippedby a user when the system is in use. The locking portion can beconfigured to work in conjunction with the guide portion to define thelocation and the trajectory of the bore to be drilled in bone, andfurther, can be configured to lock the guide system, thereby definingthe trajectory of the bore. The system can be set-up such that atrajectory of the bore can be adjusted and locked without a grip of auser on the guide portion being adjusted.

In some embodiments, the locking portion can include a carriageconfigured to slide along the guide portion. The carriage can be lockedwith respect to the guide portion without a user adjusting a grip of theuser formed on the guide portion. The guide portion can have formedtherein a plurality of slots on opposed surfaces thereof, with each slotbeing indicative of an intended trajectory for the bore to be drilledinto bone. In some embodiments, the guide portion can have formedthereon designated trajectories that correlate to the trajectory of thebore. A lowest designated trajectory for the bore can be in the range ofabout 20 degrees to about 40 degrees lower than a highest designatedtrajectory for the bore. In one exemplary embodiment, the range ofdesignated trajectories is 30 degrees.

The system can be set-up such that the locking portion can be operatedwith either hand of a user without the user having to move components ofthe system to adapt it for use with a different hand. The system canalso be set-up such that the locking portion can be operated from eitherside of a patient by a user without moving components of the system toadapt it for use from a different side.

An exemplary method for drilling a tunnel in bone includes grasping afirst arm of a ligament guide system in a palm of the hand, with fingersof the hand being wrapped around the first arm. A second end of a secondarm of the ligament guide system is positioned adjacent to a desiredlocation for a distal end of a tunnel to be drilled in bone, while afirst end of the first arm is positioned proximate to an opposed side ofthe bone, which is the side at which a proximal end of the tunnel to bedrilled in bone is to be located. A carriage disposed on the first armis slid along a length of the first arm and a location of the carriageis locked with respect to the first arm to set a trajectory of thetunnel to be drilled in bone. The carriage is able to be slid along thefirst arm while the hand grasping the first arm maintains the grasp suchthat the hand does not move with respect to the first arm. A drillingtool is passed through an opening formed in the carriage to drill atunnel in the bone from the side of the bone at which the first end ofthe first arm is located to the side of the bone at which the second endof the second arm is located.

In some embodiments, a bullet can be used in conjunction with theligament guide system. The method can include positioning a bullet inthe opening formed in the carriage and positioning a distal end of thebullet adjacent to a desired location for the proximal end of the tunnelto be drilled in bone. When the drilling tool is passed through theopening formed in the carriage, it can also be passed through thebullet. The method can further include disassociating the bullet fromthe guide arm such that the guide arm can be removed from the surgicalsite without removing the drilling tool from the bullet. The drillingtool can then be passed from the distal end of the tunnel to theproximal end of the tunnel to expand a diameter of the tunnel.

The first arm can have a plurality of slots formed in it and thecarriage can include a passively engaging male member that is configuredto engage a slot of the plurality of slots to lock a location of thecarriage with respect to the first arm to set the trajectory of thetunnel to be drilled in bone. In some embodiments, the method canfurther include actively disengaging the male member from the slot,moving the carriage along the first arm, and allowing the male member toengage a slot of the plurality of slots to lock the location of thecarriage on the first arm. In some embodiments, the first arm of theligament guide system can be configured to be grasped by either a righthand or a left hand and used to perform the method when held by eitherhand.

One exemplary instrument for setting a drill pin depth includes anelongate shaft and a depth indicator. The shaft has a proximal end, adistal end, and a channel formed in the shaft that extends from theproximal end and toward the distal end. The channel is configured toreceive a drill pin of a ligament drill guide. The depth indicator has abore formed therein that is configured to receive the elongate shaft.The indicator is configured to selectively engage the elongate shaft toset a fixed location of the depth indicator with respect to the elongateshaft. The fixed location at which the depth indicator is setestablishes a terminal distal travel location for a drill pin disposedin the channel such that the drill pin is unable to extend distally pastthe terminal distal travel location.

A distal portion of the elongate shaft can have indicia formed thereon.The indicia can be indicative of the terminal distal travel location. Adistal portion of the elongate shaft can also have a plurality ofgrooves formed thereon. In conjunction with the same, the depthindicator can include a selectively deployable groove engagement featurethat is configured to engage a groove of the plurality of grooves to setthe fixed location of the depth indicator with respect to the elongateshaft. In some embodiments, the indicia and grooves are both provided onthe distal portion of the elongate shaft. The depth indicator caninclude a button that is in mechanical cooperation with the selectivelydeployable groove engagement feature such that depressing the buttontoward the elongate shaft causes the selectively deployable grooveengagement feature to move radially away from the plurality of groovesand releasing the button causes the selectively deployable grooveengagement feature to move radially towards the plurality of grooves.

A stationary protrusion can be included as part of the depth indicator.The protrusion can be configured to fit within a channel of the elongateshaft to prevent significant rotation of the depth indicator withrespect to a longitudinal axis extending through a length of theelongate shaft. In some embodiments, a diameter or width of the channelat the proximal end of the elongate shaft can be larger than a diameteror width of the channel at a distal end of the channel.

In some embodiments, the instrument can include a drill pin and a chuckof a drill for use with the shaft and depth indicator. The drill pin canhave a distal portion and an intermediate portion each having a diameterthat is smaller than a diameter or width of the channel such that thedistal and intermediate portions are disposable in the channel, and aproximal portion configured to be coupled to the chuck of the drill. Thedrill can be configured such that a diameter of a distal portion thereofis larger than a diameter or width of the channel such that the distalportion of the drill is configured to abut the proximal end of theelongate shaft while the distal and intermediate portions of the drillpin are disposed in the channel of the elongate shaft. In aconfiguration in which the distal portion of the drill abuts theproximal end of the elongate shaft, a distal terminal end of the drillpin can be configured to abut a proximal face of the depth indicator.

One exemplary method for drilling a bore in bone can include setting adrill pin depth limit on a drill pin depth gage and attaching a drillpin to a chuck of a drill based on the set drill pin depth limit. Theresulting configuration for the drill pin being attached to the chuck ofthe drill is one in which, in use, a distal tip of the drill pin doesnot extend distally beyond the drill pin depth limit when a distalportion of the drill engages a proximal terminal end of a bullet inwhich the drill pin is disposed.

In some embodiments, the method can include determining a bone stockmeasurement, and setting a drill pin depth limit can be based on thedetermined bone stock measurement. The bone stock measurement can bedetermined, for example, by placing a distal tip of an arm of a ligamentdrill guide on a bone to be drilled at a location at which a second endof a bore is to be formed in the bone, placing a distal tip of a bulletcoupled to the ligament drill guide on the bone to be drilled at alocation at which a first end of the bore is to be formed in the bone,and reading indicia indicative of the bone stock measurement that isformed on the bullet.

The drill pin depth gage can be used in conjunction with the method caninclude an elongate shaft and a depth indicator. In such embodiments,setting a drill pin depth limit on a drill pin depth gage can includelocking a location of the depth indicator with respect to the elongateshaft to set the drill pin depth limit. Further, attaching a drill pinto a chuck of a drill based on the set drill pin depth limit can includecontacting a proximal face of the depth indicator with a distal tip ofthe drill pin, and engaging a proximal portion of the drill pin with thedrill such that the distal portion of the drill engages a proximalterminal end of the elongate shaft of the drill pin depth gage. In someembodiments that include a drill pin depth gage having an elongate shaftand a depth indicator, setting a drill pin depth limit on a drill pindepth gage can include sliding the depth indicator along the elongateshaft and selectively deploying a groove engagement feature to engage agroove of a plurality of grooves formed in the elongate shaft to lockthe location of the depth indicator with respect to the elongate shaftto set a desired drill pin depth limit.

The method for drilling a bore in bone can further include drilling abore in bone until a distal portion of the drill engages a proximalterminal end of a bullet in which the drill pin is disposed. When thedistal portion of the drill is engaged with the proximal terminal end ofthe bullet, the distal tip of the drill pin can be disposed at a distalend of the bore drilled through the bone.

The present disclosure also provides for an exemplary method forattaching a surgical drill pin to a surgical drill that is used inconjunction with a ligament drill guide and a bullet. The method caninclude determining a bone stock measurement, determining a length of abullet used in conjunction with a ligament drill guide, coupling a drillpin to a chuck of a surgical drill such that a length of the exposedportion of the drill pin distal of the chuck is equal to the bone stockmeasurement and the length of the bullet.

In some embodiment, determining a bone stock measurement can includeplacing a distal tip of an arm of a ligament drill guide on a bone to bedrilled at a location at which a second end of a bore is to be formed inthe bone, placing a distal tip of a bullet coupled to the ligament drillguide on the bone to be drilled at a location at which a first end ofthe bore is to be formed in the bone, and reading indicia indicative ofthe bone stock measurement that is formed on the bullet.

The method can also include disposing the drill pin in a drill pin depthgage. In some embodiments, the gage can be configured to be set suchthat a length of the drill pin disposed in the drill pin depth gage isequal to the length of the exposed portion of the drill pin distal ofthe chuck. In some other embodiments, the drill pin depth gage can haveindicia formed thereon to indicate the bone stock measurement. In suchembodiments, when a distal portion of the drill engages a proximalterminal end of the drill pin depth gage, a distal tip of the drill pincan be located at indicia indicative of the determined bone stock. Instill other embodiments, the drill pin depth gage can have a movabledepth indicator configured to be set at a plurality of desired locationsalong a length of the drill pin depth gage, with a desired location ofthe plurality of desired locations being based on the determined bonestock measurement. In such embodiments, coupling a drill pin to a chuckof a surgical drill can include engaging a distal tip of the drill pinwith a proximal face of the depth indicator, and engaging a distalportion of the drill with a proximal terminal end of the drill pin depthgage.

BRIEF DESCRIPTION OF DRAWINGS

This invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1A is a schematic front perspective view of one embodiment of amodular guide that exists in the prior art, the guide having a bulletassociated therewith and the guide and bullet being used in conjunctionwith a drilling instrument to form a tibial tunnel in a knee;

FIG. 1B is a schematic isometric view of the modular guide and bullet ofFIG. 1A, now being used in conjunction with the drilling instrument toform a femoral tunnel in the knee;

FIG. 2 is a front perspective view of one exemplary embodiment of amodular guide, the guide having a bullet disposed in a carriage thereof;

FIG. 3 is an isometric view of another exemplary embodiment of a modularguide, the guide having a bullet disposed in a carriage thereof;

FIG. 4A is a back perspective view of a guide arm of the modular guideof FIG. 3;

FIG. 4B is a front perspective view of the guide arm of FIG. 4A;

FIG. 5 is a detailed back perspective view of a second portion of aguide arm of the modular guide of FIG. 2;

FIG. 6 is a side perspective view of a carriage of the modular guide ofFIG. 2;

FIG. 7 is a back view of the carriage of FIG. 6 disposed on the secondportion of the guide arm of FIG. 5;

FIG. 8 is a back perspective view of the bullet of FIG. 2 disposed inthe second portion of the guide arm of FIG. 7;

FIG. 9A is an isometric view of the carriage of FIG. 3;

FIG. 9B is a side perspective view of the carriage of FIG. 9A;

FIG. 9C is a back perspective view of the carriage of FIG. 9B;

FIG. 10 is a top view of the carriage of FIG. 9A;

FIG. 11 is an exploded back perspective view of the carriage of FIG. 9A;

FIG. 12A is a front perspective view of the bullet of FIG. 3;

FIG. 12B is a back perspective view of the bullet of FIG. 3;

FIG. 13 is an isometric view of the bullet of FIG. 12A disposed in thecarriage of FIG. 9A;

FIG. 14 is an isometric view of another exemplary embodiment of acarriage of a modular guide, the carriage being disposed on the secondportion of the guide arm of FIG. 5;

FIG. 15 is a front perspective view of a proximal end of a bulletconfigured to be used with the carriage of FIG. 14;

FIG. 16A is a front perspective view of a step of securing the bullet ofFIG. 15 to the modular guide of FIG. 14;

FIG. 16B is a front perspective view of a step of advancing the bullettowards a locked position with respect to the modular guide of FIG. 14;

FIG. 16C is a front perspective view of the bullet being disposed in thelocked position;

FIG. 17A is an isometric view of one exemplary embodiment of a carriageof a modular guide;

FIG. 17B is a side perspective view of the carriage of FIG. 17A;

FIG. 17C is a back perspective view of the carriage of FIG. 17B;

FIG. 18 is a top view of the carriage of FIG. 17A;

FIG. 19 is an exploded back perspective view of the carriage of FIG.17A;

FIG. 20A is a first perspective view of one exemplary embodiment of abullet configured for use with the carriage of FIG. 17A;

FIG. 20B is a second perspective view of the bullet of FIG. 20A;

FIG. 21A is an isometric view of one exemplary embodiment of a drill pindepth gage;

FIG. 21B is a front view of the drill pin depth gage of FIG. 21A;

FIG. 21C is a side view of the drill pin depth gage of FIG. 21A;

FIG. 21D is a back view of the drill pin depth gage of FIG. 21A;

FIG. 22A is an isometric view of an indicator of the drill pin depthgage of FIG. 21A;

FIG. 22B is a side view of the indicator of FIG. 22A;

FIG. 22C is a top view of the indicator of FIG. 22A;

FIG. 22D is a cross-sectional top view of the indicator of FIG. 22C;

FIG. 23A is a schematic view of one exemplary embodiment of a modularguide and a bullet being used to measure a tibial bone stock of a knee;

FIG. 23B is a detailed side view of the bullet disposed in the modularguide of FIG. 23A;

FIG. 23C is a detailed front view of one exemplary embodiment of a drillpin depth gage set at a particular depth based on the bone stockmeasurement illustrated in FIG. 23B;

FIG. 23D is a back perspective view of the drill pin depth gage of FIG.23C having a drill pin disposed therein;

FIG. 23E is a detailed back perspective view of an indicator of thedrill pin depth gage and a distal end of the drill pin of FIG. 23D;

FIG. 23F is a detailed back perspective view of a proximal end of thedrill pin depth gage and a proximal end of the drill pin of FIG. 23D;

FIG. 23G is a schematic view of the knee of FIG. 23A illustrating apilot hole drilled by the drill pin of FIG. 23D to start a tibial tunnelusing the modular guide and bullet of FIG. 23A;

FIG. 23H is a detailed front view of the proximal end of the drill pinof FIG. 23G disposed in the bullet of FIG. 23A, which itself is disposedin the modular guide of FIG. 23A;

FIG. 23I is a detailed back view of a distal end of the drill pin ofFIG. 23G located adjacent to a distal end of a second end of a modularguide of FIG. 23A, with the knee being removed for illustrativepurposes;

FIG. 23J is a schematic view of the knee of FIG. 23G illustrating anexpanded tibial tunnel using a retrograde reamer and the bullet of FIG.23A;

FIG. 23K is a schematic view of the knee of FIG. 23J illustrating apilot hole drilled by a drill pin to start a femoral tunnel using themodular guide and bullet of FIG. 23A; and

FIG. 23L is a schematic view of the knee of FIG. 23K illustrating anexpanded femoral tunnel formed using a retrograde reamer and the bulletof FIG. 23A.

DETAILED DESCRIPTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those skilled in the art will understand that the devices andmethods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention. Further, to the extent that a componentis described using a numerical reference, e.g., “first arm” or “secondarm,” such reference does not have any significance, and thus it in noway indicates any particular order, placement, location, etc. of thecomponent with respect to any other component, object, step, etc. Infact, such numerical references can be used interchangeably. Forinstance, a component described in the specification as a “first arm” or“first portion” can be recited in the claims as a “second arm” or“second portion.” A person skilled in the art would be able tounderstand such interchangeable usage. Likewise, to the extentcomponents are described using positional references, e.g., “front end”or “back end,” such reference is not limiting to only such a view. Aperson skilled in the art would be able to understand how a side of adevice can be described as a “front end” in one view can become a side,back, top, or bottom end in another view. Such descriptions in no waylimit the perspectives described or claimed herein.

In the present disclosure, like-numbered components of the embodimentsgenerally have similar features and/or purposes. Additionally, to theextent that linear or circular dimensions are used in the description ofthe disclosed systems, devices, and methods, such dimensions are notintended to limit the types of shapes that can be used in conjunctionwith such systems, devices, and methods. A person skilled in the artwill recognize that an equivalent to such linear and circular dimensionscan easily be determined for any geometric shape. Sizes and shapes ofthe components of the modular guide systems and related components,including drill pin depth gages, can depend, at least in part, on thesizes and shapes of the other components with which the components arebeing used, the anatomy of the subject being operated on, and the typeof procedure being performed.

The present disclosure generally provides for surgical guides that canbe used in ligament repair procedures, such as repair procedures for theACL and PCL. Two exemplary embodiments of surgical guides 110, 210, alsoreferred to as modular guides, are illustrated in FIGS. 2 and 3.Surgical guides described herein generally rely on a combination of aguide arm 120, 220 and a carriage 140, 240 configured to slide along atleast a portion of the guide arm 120, 220. The carriage 140, 240 can beselectively locked at locations along the guide arm 120, 220 to set adesired location and trajectory for a bone tunnel or bore to be drilledin conjunction with a ligament repair procedure. The carriage 140, 240can also be configured to receive a bullet 170, 270, which itself can beused in conjunction with the guide 110, 210 to set the desired locationand trajectory of the bone tunnel or bore to be drilled. The termstunnel and bore will be used interchangeably throughout thespecification as it pertains to forming a hole in a bone.

While more detail about two configurations illustrated in FIGS. 2 and 3are provided below, one of the primary differences between the twoconfigurations is the construction of the carriages 140, 240, and inparticular how the carriages are configured to receive a bullet. Thecarriage 140 of FIG. 2 includes a bullet-receiving opening 142 that isgenerally configured to receive a bullet 170 inserted from the top, asshown through a proximal end 140 p of the carriage 140, and insertedtowards a distal end 140 d of the carriage 140. The carriage 240 of FIG.3 includes a bullet-receiving opening 242 that is generally configuredto receive a bullet inserted from a side of the carriage, as shown afront-facing or first facial surface 250 f (which is visible better inFIG. 9A), such that the bullet passes from an outside environment,across a plane P₁ extending substantially through the first facialsurface 250 f, and into the bullet-receiving opening 242.

The configurations illustrated in FIGS. 2 and 3, as well as thevariations thereof described herein or otherwise derivable therefrom,provide a number of benefits in comparison to existing guides, such asthe guide 10 illustrated in FIGS. 1A and 1B. The interaction between thecarriage and the guide arm creates a secure locked position thatestablishes the trajectory of the bone tunnel and that is not likely tobe disengaged unintentionally during use. Thus, the likelihood of thebone tunnel being drilled inaccurately through the bone tunnel whetherthrough divergence or otherwise is decreased. The configuration of theguide is also such that it can be easily operated by a surgeon withoutthe surgeon needing to switch hands or replace components of the guideto perform various tasks during a surgical procedure. In fact, unlikeprevious guides, the guides provided for herein are universal in thatthe same guides can be used easily in a surgeon's right-hand orleft-hand on either knee of a patient to form both the tibial andfemoral tunnels without having to change parts or shift grips to easilyoperate the guide. Still further, the disclosed designs allow the angleor trajectory of the bone tunnel to be defined by a portion, e.g., thecarriage, that is separate from the portion held be a user duringtypical operation of the device. These benefits of the disclosed guides,as well as others, are evident from the descriptions below.

The present disclosure also provides for a drill pin depth gage that canbe used in conjunction with the guides described herein or guides knownin the prior art. Two exemplary embodiments of a drill pin depth gage380, 480 are provided in FIGS. 21A and 23C-23F herein. The gagesprovided for herein or otherwise derivable therefrom improve the way bywhich a bone tunnel is drilled in bone by enabling a user to easilyprevent a drill pin used to drill the tunnel from traveling too far. Adrill pin that extends distally too far past the bone tunnel can causedamage to surrounding tissue and the like, e.g., femoral articularcartilage and neurovascular structures. More particularly, the guideenables the user to accurately set the location of the drill pin withrespect to a drill chuck so that the drill pin cannot travelsubstantially beyond the intended distal end of the bone tunnel, andthus prevents unintended contact with surrounding tissue.

Turning back to the embodiments of the surgical guides 110, 210, eachgenerally includes a guide arm 120, 220 with a carriage 140, 240disposed on a portion thereof. The arm 120, 220 can be considered tohave a first portion 122, 222 and a second portion 124, 224 with anangle α, α′ that can be approximately 110 degrees or less extendingbetween the two portions. Alternatively, the portions can be describedas a first arm and a second arm, respectively. The first arm or portion122, 222 can operate in conjunction with the carriage 140, 240 to definean angle at which the bone tunnel is to be drilled into bone, sometimesreferred to herein as the trajectory of the bone tunnel, while a tip126, 226 disposed at a distal or second end 124 b, 224 b of the secondarm 124, 224 can define a location of a distal end of the bone tunnel tobe drilled. As shown, the carriage 140, 240 is disposed on the first arm122, 222 and can translate along a length thereof, and it canselectively lock along the arm to set the bone tunnel trajectory. Thecarriage can have an opening 142, 242 to receive a bullet 170, 270,which can work in conjunction with the first arm 122, 222 and thecarriage 140, 240 to more easily establish the trajectory for thedrilling component, e.g., a drill pin or reamer, to enter the bone. Adistal end 170 d, 270 d of the bullet 170, 270 can also be disposedadjacent to a proximal end of the intended bone tunnel to define theentry location for the drilling component.

The two components of the guide 110, 210—the guide arm 120, 220 and thecarriage 140, 240—as well as the bullet 170, 270, are described infurther detail below with respect to at least one of the two embodimentsillustrated in FIGS. 2 and 3. The bullet can be considered to be part ofthe guide, or it can be considered as a separate component, separatefrom the guide. Generally, the guide arm, carriage, and bullet can beconsidered to be core components of a surgical or modular system. Thus,disclosures provided for herein that allow for a universal system inwhich core components do not have to be replaced or reconfigured for usein the right or left hand allows for components like the guide arm,carriage, and bullet to be used without replacing or reconfiguring them.A person having ordinary skill in the art will recognize that many ofthe teachings provided for one embodiment of the guides 110, 210 areequally applicable to both embodiments, as well as other embodimentsprovided for herein or otherwise derivable from the present disclosure.

Further, the disclosures herein discuss various features that can assistwith guiding and locking the guide system. Generally, a guide portion ofthe system can be any component that defines a location and a trajectoryof a bore to be drilled in the bone and is configured to be gripped by auser when the system in use. Guide portions include, but are not limitedto, the guide arm (e.g., guide arms 120, 220, among others) of thesystem. Generally, a locking portion can be any component configured towork in conjunction with the guide portion to define the location andthe trajectory of the bore to be drilled in the bone and is configuredto lock the guide system to finalize or otherwise define the trajectoryof the bore. Locking portions include, but are not limited to, thecarriage (e.g., carriages 140, 240) and/or bullets (e.g., bullets 170,270). In some instances, the components can be both a guide portion anda locking portion. For example, sometimes a carriage can be both a guideportion and a locking portion.

Guide Arm

The guide arm 220 from FIG. 3 is illustrated in FIGS. 4A and 4B. A firstportion (or arm) 222 is generally configured to engage with a carriageso the carriage can be translated along a portion of the first portion'slength, while a second portion (or arm) 224 is configured to bend aroundto another side of a bone in use to serve as an indicator of where thedistal end of the bone tunnel should be formed.

As shown, the first arm 222 is generally arcuate and has two facialsurfaces 222 f, 222 g that are generally parallel to each other and twosidewalls 222 r, 222 s extending therebetween, which are also generallyparallel to each other. The surfaces of the facial surfaces 222 f, 222 gand the sidewalls 222 r, 222 s can be substantially flat and can have asubstantially consistent width w and height h across a length l of thefirst arm 222. In the illustrated embodiment the arcuate nature of thearm 222 is such that it maintains a radius of curvature R that issubstantially the same across the entire length l of the arm, althoughin other embodiments only a portion of the arm 222 may be arcuate or thearm may have varying radii of curvature across its length. One end 222 aof the first arm 222, which forms a terminal end of both the first arm222 and the guide 210, has a curved configuration, while the second,opposed end 222 b of the first arm 222 is configured to mate with thesecond arm 224. For example, the first arm 222 can have a male memberformed at its end 222 b that is configured to be received by acomplementary female member formed at a first end 224 a of the secondarm 224.

A person having ordinary skill in the art will recognize that there aremany other ways by which the first and second arms 222, 224 can beconnected. For example, as shown in the FIG. 2 embodiment, the first andsecond arms 122, 124 are held together by a coupling device 128, such asa band or clamp, to maintain one arm at a set location with respect tothe other. In some embodiments, the first and second guide arms 122, 222and 124, 224 can be of a singular construction such that they are thesame piece. More generally, as used herein, the term unitaryconstruction encompasses embodiments that are of a singular constructionas well as embodiments in which the first arm is coupled to the secondarm in some manner to form a unitary arm. The unitary construction issuch that the first and second arms are not moved with respect to eachother to adjust an intended angle or trajectory of the bone tunnel to bedrilled. Further, neither the first nor second arm are moved withrespect to a component configured to be held by the user, such as aframe, to adjust an intended angle or trajectory of the bone tunnel tobe drilled.

One or more engagement features can be formed on at least a portion ofthe first arm 222. In the embodiment illustrated in FIGS. 4A and 4B, theengagement feature is a plurality of slots 230 (e.g., six slots) formedat a location near the terminal end 222 a of the arm 222, closer to theterminal end 222 a than then second end 222 b. Each slot serves as alocation at which the carriage can be locked with respect to the arm 222to achieve a particular angle for the trajectory of the bone tunnel. Aperson having skill in the art will recognize the significance of thenumbers used to define the trajectories or angles identified on thefirst arm 222. The numbers are useful to the surgeon based on thereference point the surgeon is using to define the actual trajectory ofthe bone tunnel. Accordingly, just because a trajectory is set at aparticular number on the first arm e.g., 75 degrees, does not mean thatan angle formed between the bullet and the bone, the bullet and aparticular portion of the second arm, or any other particular dimensionis 75 degrees. A person having skill in the art using the guide 210 willunderstand the significance of the defined trajectory for his or her ownparticular purposes.

As shown in FIGS. 4A and 4B, the slots 230 provided allow for anglesbetween 95 degrees and 120 degrees, with each slot being spaced fromrespective slots such that the provided for angles are five degreesapart from each other. Slots 130 formed in the first arm 122 of theguide 110 of FIG. 5 allow for angles between 45 degrees and 70 degrees,again with each slot being spaced from respective slots such that theprovided for angles are five degrees apart from each other. Similar tothe guide 210, the first guide 110 can include the first and second arms122 and 124. As shown in FIG. 5, the first arm 122 can include twofacial surfaces 122 f, 122 g (122 g is not visible) and two sidesurfaces 122 r, 122 s (122 s is not visible), with the slots 130 beingformed proximate to a terminal end 122 a. While the illustratedembodiments show trajectory ranges between 95 degrees and 120 degreesand between 45 degrees and 70 degrees, a person skilled in the art willrecognize a wide variety of trajectory options that are possible, withthe range being anywhere from about 15 degrees to about 165 degrees, andwith each slot having a degree difference therebetween approximately inthe range of about 1 degree to about 25 degrees. In some embodiments, asingle slot may be desirable so that a consistent trajectory is used foreach procedure with that arm. Further, although in the illustratedembodiment the engagement feature(s) includes slots, other engagementfeatures known to those skilled in the art can also be used in place ofor in conjunction with slots without departing from the spirit of thepresent disclosure.

Indicia 132, 232 can be formed or otherwise indicated on the first arm122, 222, adjacent to the slots 130, 230, so a user knows the angleassociated with the respective slot. In alternative embodiments, indiciacan be used in lieu of slots. The angles established by the device 110,210 can depend on a variety of factors, including but not limited to thelocation of the slots 130, 230 on the first arm 122, 222, the radius ofcurvature R, R′ of the portion of the first arm 122, 222 in which theslots 130, 230 are formed, and the configuration of the carriage withwhich the arm 120, 220 is used.

The slots 130, 230 themselves are indentations formed in the facialsurfaces 122 f, 222 f and 122 f, 122 g of the arm 122, 222, and thusthey serve as female mating elements. The slots 130, 230 can beconfigured in a variety of ways, but they generally have a configurationthat is complementary to a male member of the carriage (a key 164, asshown in FIG. 6, for the arm 222) with which the female slots engage. Inthe illustrated embodiments, but labeled only in FIG. 5, eachindentation is slightly tapered such that a height a of a sidewall 130s, 230 s of each slot 130, 230 proximate to an entry opening 130 e, 230e of the slot is slightly higher than the height a of the sidewall 130s, 230 s proximate to a terminal end 130 t, 230 t of the slot. Such aconfiguration makes it easier for the male member of the carriage tolock into the desired female slot 130, 230 because the pocket at theentry opening 130 e, 230 e is deep enough to catch the male member whilethe pocket at the terminal end 130 t, 230 t is deep enough to maintainthe male member therein until the male member is affirmatively removedfrom the slot. In fact, such a configuration helps to allow for apassive locking configuration in which the carriage can be locked at adesired trajectory along the first arm without a user actively engagingthe male member of the carriage to lock into the slot.

As shown in FIGS. 4A and 4B, the slots 230, as well as the indicia 232associated with the slots 230, can be formed in both facial surfaces 222f, 222 g of the first arm 222. Even though the carriage is only designedto engage a slot on one side of the arm, providing slots 230 on bothfacial surfaces 222 f, 222 g creates a universal configuration thatallows the same guide to be easily used by right-handed and left-handedusers without making significant adjustments to the core components,e.g., nothing more than flipping the direction of the carriage for rightand left-handed users. Such a configuration also makes it easier for auser to use the device on either the left knee or the right knee to formboth the tibial and femoral tunnels, regardless of where the user islocated with respect to the knee. A surgeon can thus perform a procedurewith the same device from the same location in the operating roomwithout moving to a different location in the room and without having toreplace or adjust one or more of the core components of the guide, i.e.,the guide arm, the carriage, and/or the bullet. In other embodiments,carriages can be configured to engage slots on both sides of the arm toprovide an even more secure locked position, or alternatively, the armcan have slots formed in only one side of the arm, for instance to makemanufacturing quicker and less expensive.

The first arm 222 can also include features to assist a user in grippingthe device 210. The device 210 is generally configured in a manner thatallows the first arm 222 to sit in a palm of a user's hand at a grippinglocation 234 further down the length of the arm 222 than the slots 230,away from the terminal end 222 a, with a user's fingers wrapped aroundthe arm 222 at this location as well. In the illustrated embodiment achamfer 236 is formed in the arm 222 at the gripping location 234 toprovide a comfortable grip for the user. The chamfer 236 can be providedon both sides of the arm 222 as shown, thus providing additionalfeatures that allow for the device 210 to be used universally, i.e.,with either hand, in conjunction with a procedure performed on eitherknee to form both the tibial and femoral tunnels, regardless of wherethe user is located with respect to the knee, and without having toreplace or reconfigure core components of the device. A person skilledin the art will recognize other features that can be incorporated intothe arm to assist a user in gripping the device. By way of non-limitingexample, in some embodiments finger grips or grooves can be formed atthe gripping location 234 to provide a location at which the fingers ofa user can be positioned when holding the device 210.

The second portion or arm 224 mates to the first arm 222 to form aunitary configuration, as described above. Further, the second arm 224can be disposed at an angle α′ with respect to the first arm 222, theangle being formed in a plane P₂ that extends substantially through thefacial surfaces 222 f, 224 f of the first and second arms 222, 224. Moreparticularly, the angle between the first and second arms 222, 224 canbe approximately 110 degrees or less. A person skilled in the art willrecognize that the angle α′ for a guide arm used to form a tibial tunnelis typically different than the angle α′ for a guide arm used to form afemoral tunnel. In some embodiments, the angle between the arms is inthe range of about 60 degrees to about 110 degrees, and in one exemplaryembodiment the angle is about 105 degrees for a femoral tunnel and about90 degrees for a tibial tunnel. The angle formed between the first andsecond arms 222, 224 can assist in allowing access to a desired locationin the body, such as the knee. More particularly, the angle allows abullet to be associated with the guide arm 220 such that a distal end ofthe bullet can be disposed at a desired location for the proximal end ofa bone tunnel and the distal end 224 b of the second arm 224 can bedisposed at a desired location for the distal end of the bone tunnel.The angle α′ can also be different for guide arms used in other contextsoutside of the tibia and femur.

The second arm 224 can have a variety of configurations. As shown, ithas an arcuate configuration, particularly towards its distal end 224 b,which allows the second arm 224 to be positioned at a location proximateto a desired location for the distal end of the bone tunnel. In theillustrated embodiment, the second arm 224 includes two facial surfaces224 f, 224 g substantially parallel with respect to each other and twosidewalls 224 r, 224 s extending therebetween, which are alsosubstantially parallel with respect to each other. As used herein, theterm substantially parallel does not necessarily mean exactly parallel,at least because of various tapers that may exist across one or more ofthe surfaces being described as being involved in a substantiallyparallel configuration. For example, in some embodiments the firstfacial surface 224 f may be tapered towards a central longitudinal axisof the housing 250 from the proximal end 250 p to the distal end 250 dso that a distal tip of a bullet disposed in the housing can be seatedapproximately within the plane P₂ that extends through the guide, asdescribed in greater detail below. A pointed distal tip 226 can bedisposed at the terminal or second end 224 b of the second arm 224, andcan be used to define a location of a distal end of the bone tunnel tobe drilled. It can also be used to indicate to a user passing a drillpin or other cutting device from the first arm 222 and to the terminalend 224 b of the second arm that the terminal end 224 b has been reachedso that the cutting device is not further distally advanced. In someembodiments the tip 226 can be blunter to help stop a distally advancingcutting or drilling device. In still other embodiments the distal tip ofthe second arm can be a partial circle, e.g., a C-shape, or a fullcircle that defines an opening through which the drill pin is received.

A first end 224 a of the second arm 224 can have a configuration that issimilar to the second end 222 b of the first arm 222 to make couplingthe first arm to the second arm easy. Thus, the transition from one armto the next is smooth. As shown, a gripping feature such as the chamfer236 can extend onto a portion of the second arm 224 such that the firstend 224 a of the second arm 224 is part of the gripping location 234. Aremaining portion of the second arm 224, however, can be thinner alongits length so that the arm is less obtrusive when disposed in the body.As shown, both a height h′ and a width w′ of the second arm tapers alonga length l′ of the second arm 224 such that the height h′ and width w′at the distal end 224 b are less than the height h′ and width w′ at thefirst end 224 a. In some embodiments the length l′ of the second arm 224can be similar to the length l of the first arm 222, although in otherembodiments one of the arms can be longer than the other.

A person having ordinary skill in the art will recognize a variety ofother configurations that can be used to form the guide arm withoutdeparting from the spirit of the present disclosure. Bearing that inmind, in some embodiments, such as the guide arms 120, 220 illustratedherein, a length l of the first arm 122, 222, measured from opposed tipsas illustrated in view of the arcuate nature of the arm, can beapproximately in the range of about 10 centimeters to about 15centimeters, a width w of the first arm 122, 222 can be approximately inthe range of about 10 millimeters to about 30 millimeters, and a heighth of the first arm 122, 222 can be approximately in the range of about 5millimeters to about 10 millimeters, with a radius of curvature R beingapproximately in the range of about 90 millimeters to about 120millimeters. In one exemplary embodiment the first arm 122, 222 has alength l of about 12 centimeters, a width w of about 13 millimeters, aheight h of about 6 millimeters, and a radius of curvature R of about108 millimeters. Each slot can have a length h (FIG. 5) approximately inthe range of about 3 millimeters to about 10 millimeters, a width x(FIG. 5) approximately in the range of about 3 millimeters to about 10millimeters, and a tapering height v (FIG. 5) approximately in the rangeof about 3 millimeters to about 8 millimeters at its greatest andsmallest heights. In one exemplary embodiment, each slot has a length yof about 5 millimeters, a width x of about 4 millimeters, and a height vproximate to the entry opening 130 e, 230 e of about 6 millimeters and aheight v proximate to the terminal end 130 t, 230 t of about 5millimeters.

Likewise, in some embodiments, such as the guide arms 120, 220illustrated herein, a length l′ of the second arm 124, 224, measuredfrom opposed tips as illustrated in view of the arcuate nature of thearm, can be approximately in the range of about 10 centimeters to about15 centimeters, a width w′ of the second arm 124, 224 can beapproximately in the range of about 3 millimeters to about 15millimeters, with the width w′ decreasing along its length from thefirst end 124 a, 224 a to the second end 124 b, 224 b, a height h′ ofthe second arm 124, 224 can be approximately in the range of about 2millimeters to about 8 millimeters, again with the height h′ decreasingalong its length from the first end 124 a, 224 a to the second end 124b, 224 b, and a radius of curvature R′ proximate to the second end 124b, 224 b approximately in the range of about 0 millimeters to about 46millimeters. In one exemplary embodiment the second arm 124, 224 has alength l′ of about 13 centimeters, a width w′ of about 11 millimeters atthe first end 124 a, 224 a and of about 4 millimeters at the second end124 b, 224 b, a height h′ of about 6 millimeters at the first end 124 a,224 a and of about 4 millimeters at the second end 124 b, 224 b, and aradius of curvature R′ proximate to the second end 124 b, 224 b of about46 millimeters. Further, first and second arms 122, 222 and 124, 224 ofthe guide arm 120, 220 can be made from a variety of materials,including but not limited to surgical grade metals such as stainlesssteel and titanium, or various polymers. In some embodiments the armscan be made from the same material, while in other embodiments they canbe made from different materials.

Carriage

FIG. 6 illustrates one exemplary embodiment of a carriage 140, thecarriage 140 being of the nature illustrated in FIG. 2, i.e., it isconfigured to receive a bullet in the bullet-receiving opening 142 fromthe proximal end 140 p thereof. Notably, the carriage 140 is a separatecomponent of the device 110 from the portion of the device generallyheld by a user during use, i.e., the guide arm 120, which makes thedevice 110 easier to use and more accurate than devices that include thecomponent that defines the trajectory of the bone tunnel as part of theportion generally held by a user during use, such as the device 10illustrated in FIGS. 1A and 1B. The carriage 140 generally includes ahousing 150, a bullet-receiving opening or channel 142, and aguide-receiving opening 144 for being disposed on the guide arm, e.g.,guide arm 120. The housing 150 can have many different shapes and sizes,which can depend, at least in part, on the configuration of the devicecomponents with which it is being used, the anatomy of the patient, andthe type of procedure with which it is being used. In the illustratedembodiment, the housing 150 can generally be described as having theshape of a trapezoidal prism that includes a proximal end 150 p, adistal end 150 d, two opposed facial surfaces 150 f, 150 g extendingbetween the proximal and distal ends 150 p, 150 d, and two opposed sidesurfaces 150 r, 150 s extending between the two facial surfaces 150 f,150 g and the proximal and distal ends 150 p, 150 d. Each of thesesurfaces need not be continuous, as discussed in greater detail below.By way of non-limiting example, the second facial surface 150 g in theillustrated embodiment includes an upper portion 150 a and a lowerportion 150 b that are not continuous, but together with a guideengaging mechanism 160, these two portions 150 a, 150 b form a wall ofthe guide-receiving opening 144 that extends from one side surface 150 rto the other side surface 150 s. As shown, an outer surface 160 g of theguide engaging mechanism 160 extending between the upper and lowerportions 150 a, 150 b and facing outward is not flush with outersurfaces of the upper and lower portions 150 a, 150 b, although it couldbe in other configurations.

As shown, a length L of the housing 150 is defined by the distancebetween the proximal and distal ends 150 p, 150 d, which is also alength of the first and second facial surfaces 150 f, 150 g and a lengthof the first and second sidewalls 150 r, 150 s. In the illustratedembodiment, the lengths of the facial surfaces 150 f, 150 g and thesidewalls 150 r, 150 s are substantially equal. A thickness T of thehousing 150 is defined by the distance between the first and secondsidewalls 150 r, 150 s, which is also a width of the first and secondfacial surfaces 150 f, 150 g and a length of the proximal and distalends 150 p, 150 d. As shown in FIG. 7, the thickness T of the housing150 at the proximal end 150 p is greater than the thickness T at thedistal end 150 d. A width W of the housing 150 is defined by thedistance between the first and second facial surfaces 150 f, 150 g,which is also a width of the side surfaces 150 r, 150 s and a width ofthe proximal and distal ends 150 p, 150 d. As shown in FIG. 8, the widthW of the housing at the proximal end 150 p is greater than the width Wat the distal end 150 d. Generally, the length L of the housing 150 islarger than the thickness T and width W of the housing 150, although itdoes not necessarily have to be. A longer housing can help to moresecurely seat the bullet though.

The bullet-receiving opening or channel 142 can be formed in the firstfacial surface 150 f. As shown, the bullet-receiving opening 142 extendslongitudinally from and through the proximal end 150 p to and throughthe distal end 150 d and has a substantially cylindrical shape that iscomplementary in shape to the bullet 170 it is configured to receive.Likewise, a diameter of the opening 142 is such that it is sized toreceive a bullet therein. In the illustrated embodiment, a diameter ofthe bullet-receiving opening 142 is less than half the size of the widthW of the housing. Further, the bullet-receiving opening 142, and thefirst facial surface 150 f in which it is formed, can be tapered fromthe proximal end 150 p to the distal end 150 d to help align a bulletdisposed therein with the desired location for the proximal end of thebone tunnel. That is, because the carriage 140 extends away from theplane P₂ extending substantially through the facial surfaces 122 f and124 f of the first and second arms 122, 124, a slight taper in the firstfacial surface 122 f and/or the bullet-receiving opening 142 can helpdirect a distal end of a bullet to be in the plane P₂ at the surgicalsite. As a result, the distal end 170 d of the bullet 170 can beproperly aligned with the distal tip 126 to allow for the bone tunnel tobe properly aligned between the proximal and distal ends of the bonetunnel. A degree of the taper can be approximately in the range of about1 degree to about 8 degrees with respect to the plane P₂, and in someembodiments the degree of taper is about 3 degrees with respect to theplane P₂.

The guide-receiving opening 144 can extend substantially transverse tothe bullet-receiving opening 142, extending through the housing 150 fromand through the first side surface 150 r to and through the second sidesurface 150 s, with the opening 144 being defined by an inner wall ofthe proximal end 150 p, an inner wall of the distal end 150 d, an innerwall of the first facial surface 150 f, and an inner wall of the secondfacial surface 150 g, e.g., predominately by an inner wall of the guideengaging mechanism 160. As shown, the guide-receiving opening 144 andthe bullet receiving opening extend in different planes. A size andshape of the guide-receiving opening 144 can be complementary to thesize and shape of the first arm 122 of the guide arm 120 such that thefirst arm 122 can extend through the guide-receiving opening 144 and thecarriage 140 can be securely locked at one or more locations along alength of the first arm. In the illustrated embodiment, a length L ofthe carriage 140 can extend substantially transverse to a length l ofthe first arm 122. As used herein, the term substantially transversedoes not necessarily mean exactly transverse, at least because of thearcuate configuration of the first arm 122. A person skill in the artwill understand that such a description is generally intended to addressthe fact that, as shown, the length L of the carriage 140 is notgenerally disposed in the same direction as the length of the first arm122.

As indicated above, the second facial surface 150 g can be partiallyformed by a surgical guide engaging mechanism 160. In the illustratedembodiment the surgical guide engaging mechanism 160 includes a bar 162that is opposed substantially parallel to the first facial surface 150f, although not necessarily exactly parallel in embodiments in which thefirst facial surface 150 has a slight taper with respect to the plane P₂as described above. The bar 162 can include a male member formedthereon, as shown a selectively deployable key 164, having a shape andsize that is complementary to a shape and size of the female memberformed on the arm guide 120, as shown in FIGS. 7 and 8, the plurality ofslots 130.

The surgical guide engaging mechanism 160 can serve as a passive lockingengagement mechanism. In conjunction with the same, a spring-loadedbutton 166 can be formed at a proximal end 160 p of the guide engagingmechanism 160. The button 166 can be configured to move the key 164along a longitudinal axis LA of the housing such that when the button166 is depressed towards the distal end 140 d of the carriage 140, asshown in FIG. 7, the carriage 140 can freely translate along the guidearm 120, including over and past the slots 130 formed in the first arm122. However, when the button 166 is not depressed, as shown in FIG. 8,the carriage 140 can only slide along the guide arm 120 until the key164 is biased back into one of the slots 130, i.e., the key 164passively engages a slot 130.

As the key 164 becomes properly seated in a slot 130 to place thecarriage 140 in a locked position, two forces are applied to the guidearm. As illustrated in FIG. 8, a first force in a direction M, which isapproximately perpendicular to the second facial surface 122 g of thefirst arm 120, causes the carriage 140 to push down against the guidearm 120, and a second force in a direction N, which is approximatelyperpendicular to the direction M and substantially parallel to thesecond facial surface 122 g, causes the carriage 140 to push the guidearm 120 back. As a result, the carriage 140 is firmly locked into placewith respect to the guide arm 120, and in turn reduces the risk of drillpin divergence without having to rely heavily on spring forces or tighttolerances, which can wear away over time. When the carriage 140 is inthe locked position, the carriage 140 cannot advance along the length ofthe first arm 122, and it is also restricted from traveling along thelongitudinal axis LA of the housing 150.

The button 166 can have a variety of shapes and sizes, but generally itcan be configured so that it can be pressed by a thumb of a user. In theillustrated embodiment, a length L_(B) of the button 166 is similar tothe width W of the housing 150, and a width W_(B) of the button 166 isapproximately half the width W of the housing 150. Springs can bedisposed in the housing 150 to bias the button 166, and thus the key164, in a desired direction. In the illustrated embodiment, two springsare disposed along the length of the surgical guide engaging mechanism160 and bias the button 166, and thus they key 164, in a direction Q,proximally away from the proximal end 140 p of the carriage 140. Thesurgical guide engaging mechanism 160 can also include an opening 168formed in the bar 162. The opening 168 can be configured so that theindicia 132 formed near the slots 130 can be easily read when thecarriage 140 is disposed on the first arm 122, as shown in FIG. 7. Insome embodiments, the opening 168 can allow a user see when the key 164is about to or is engaging one of the slots 130.

The carriage 140 not only locks a location of the carriage 140 withrespect to the guide arm 120, but it can also lock a location of abullet disposed therein. More specifically, in the illustratedembodiment, the bullet 170 disposed in the bullet-receiving opening 142is locked with respect to the length l of the first arm 122 and theheight h of the first arm such that the bullet 170 cannot travel inthese directions. The bullet 170 can travel along the length l of thefirst arm 122, however, when the carriage is operated to translate alongthe arm 122, as described above. Further, the carriage 140 can beconfigured to allow the bullet 170 to travel proximally and distallyalong the longitudinal axis LA, regardless of whether the carriage is ina translating or locked configuration. This allows the distal tip 170 dof the bullet 170 to be positioned adjacent or proximate to the bone inwhich the bone tunnel is to be formed. This location can define theproximal end of the bone tunnel, and can also be used to help to measurebone stock, i.e., the thickness of the bone to be drilled, which in turnbecomes the length of the bone tunnel, as described in greater detailbelow.

Side-Loading Carriage

A second embodiment of a carriage 240 is illustrated in FIGS. 9A-11.Similar to the carriage 140, the carriage 240 is a separate component ofthe device 210 from the portion of the device generally held by a userduring use, i.e., the guide arm 220, which makes the device 210 easierto use and more accurate than devices that include the component thatdefines the trajectory of the bone tunnel as part of the portiongenerally held by a user during use, such as the device 10 illustratedin FIGS. 1A and 1B. The carriage 240 includes a housing 250 that canhave many different shapes and sizes, which can depend, at least inpart, on the configuration of the device components with which it isbeing used, the anatomy of the patient, and the type of procedure withwhich it is being used. Similar to the housing 150 of the carriage 140,the housing 250 has the shape of a trapezoidal prism that includes aproximal end 250 p, a distal end 250 d, two opposed facial surfaces 250f, 250 g extending between the proximal and distal ends 250 p, 250 d,and two opposed side surfaces 250 r, 250 s extending between the twofacial surfaces 250 f, 250 g and the proximal and distal ends 250 p, 250d. Again, similar to the housing 150, each of the identified surfacesneed not be continuous, e.g., the second facial surface 250 g caninclude an upper portion 250 a and a lower portion 250 b that are notcontinuous, and a portion of a guide engaging mechanism 260, as shown anouter surface 260 g, can extend between the two portions 250 a, 250 b toform a wall of a guide-receiving opening 244 that extends through thehousing 250 from one side surface 250 r to the other side surface 250 s.A length L′, a width W′, and a thickness T′ of the housing 250 can bedefined by the same distances described above with respect to thehousing 150, and as illustrated in FIGS. 9A-9C and 10. Typically thelength L′ is greater than the width W′ and the thickness T′.

The carriage 240 also includes a bullet-receiving opening 242 and aguide-receiving opening 244. More particularly, the bullet-receivingopening 242 is formed within a rotatable receiver 246, which isrotatably disposed within the housing 250. An opening 241 can be formedin the first facial surface 250 f to receive the rotatable receiver 246.As shown, the opening 241 can include a main receiving portion 241 m anda track portion 241 t formed in the proximal end 250 p of the housing250. The track portion 241 t can have a diameter that is bigger than themain receiving portion 241 m so that a proximal end 246 p of therotatable receiver 246 can sit within the track portion 241 t and rotatewith respect to the same.

In use, the rotatable receiver 246 rotates with respect to the housing250 between a first position, also referred to as a receiving position,in which it is open to the outside environment so it can receive abullet therein, and a second position, also referred to as a lockingposition, which is illustrated in FIGS. 9A-9C and 10, in which a bulletreceived by the rotatable receiver 246 is disposed in its lockedposition such that the bullet is locked in at least two planes withrespect to the carriage 240. More particularly, the bullet in the lockedposition cannot translate between the first and second facial surfaces250 f, 250 g or between the first and second side surfaces 250 r, 250 s.The rotatable receiver 246 also includes an intermediate positiondisposed between the receiving and locking positions, in which a bulletis disposed in the rotatable receiver 246 and is also unable totranslate between the first and second facial surfaces 250 f, 250 g orbetween the first and second side surfaces 250 r, 250 s. However, asdescribed in further detail below, in the locked position the bullet canonly translate distally, towards distal end 250 d, and not towards theproximal end 250 d, while in the intermediate position the bullet canfreely translate both distally and proximally.

While the rotatable receiver 246 can have a variety of shapes and sizes,depending, at least in part, on the configurations of the housing,bullet, and other related components and the type of procedure in whichthe carriage is being used, in the illustrated embodiment the rotatablereceiver 246 has a generally cylindrical shape that is complementary inshape to the portions of the housing 250 in which it is disposed, i.e.,the opening 241. Accordingly a main body 246 m of the rotatable receivercan be shaped such that it can sit within the main receiving portion 241m of the opening 241 and can rotate within the opening. A proximal end246 p of the rotatable receiver 246 can include a cylindrical guide thatis configured to be received in the track portion 241 t of the opening241. As shown, the proximal end 246 p can have a diameter that is largerthan a diameter of the main body 246 m because in the illustratedembodiment a diameter of the track portion 241 t is larger than adiameter of the main receiving portion 241 m. Further, as shown, theproximal end 246 p can include opposed indents 246 i. The indents 246 ican allow the rotatable receiver 246 to receive a portion of a ramp 233used to help lock a location of the rotatable receiver 246 with respectto the housing 250, as described in greater detail below. Additionally,a diameter of the main body 246 m can be tapered such that a diameter ofthe main body 246 m adjacent to the proximal end 246 p is larger than adiameter of the main body 246 m at a distal end 246 d of the rotatablereceiver 246. This taper can be complementary to a taper formed in themain receiving portion 241 m and/or the housing 250 itself, and can beconfigured to help align a bullet disposed in the bullet-receivingopening 242 with a desired proximal end of the bone tunnel to be formed,similar to the taper discussed above with respect to the carriage 140 ofFIGS. 6-8. The degree of the taper with respect to the plane P₁′ (notshown) that extends substantially through the facial surfaces 222 f, 224f when the carriage is disposed on the first arm 222 can likewise besimilar.

The rotatable receiver can include features to help secure a bulletwithin the bullet-receiving opening 242. One such feature can be aprotrusion, as shown a pin 239, that extends into the channel 242 at adeepest, central part of the channel, and can be complementary to a slotor groove formed in a bullet such that pin 239 can sit within the slotor groove of the bullet to help maintain a location of the bullet withrespect to the rotatable receiver 246. When a bullet is secured by thepin 239, for instance by rotating the bullet within the channel 242 asdescribed in greater detail below, incidental force applied to thebullet will not cause the bullet to rotate around the channel 242. Insome embodiments, the materials of the pin and the bullet can be suchthat an audible sound is emitted once the pin 239 is disposed within theslot, thereby informing the user that the bullet is secured with respectto the rotatable receiver 246. The pin 239 can be disposed within a bore237 formed in a wall of the rotatable receiver 246, or it can beassociated with the rotatable receiver 246 using a variety of differenttechniques known to those skilled in the art. In the illustratedembodiment the pin 239 is disposed at a location in the proximal half ofthe rotatable receiver 246, although the pin 239 can be disposedanywhere along the length of rotatable receiver 246 without departingfrom the spirit of the present disclosure.

The rotatable receiver 246 can also include features to help hold thereceiver 246 in a locking position and/or to help remove the rotatablereceiver 246 from the locking position. One such feature is a groove ortrack 235 formed in an outer surface of the rotatable receiver 246. Asshown, the track 235 extends around the outer surface from one end ofthe channel 242 to the other end of the channel 242, the track 235 beingopposed to the channel 242. The track 235 is disposed in a location thatallows it to work in conjunction with one or more ramps 233 provided forin the housing 250 to hold the rotatable receiver 246 in the lockingposition. As shown, the track 235 is in the proximal half of therotatable receiver 246 and is disposed proximal of the pin 239.

The ramp used in conjunction with the features of the rotatable receiver246, e.g., the indents 246 i, to hold the receiver 246 in a lockingposition and/or to help remove the receiver 246 from the lockingposition can have a variety of configurations. As shown, the ramp 233 ofthe carriage is formed by the combination of a rod 233 r and a button233 b. More particularly, the rod 233 r can extend through acomplementary opening 231 formed in the housing 250, adjacent to theopening 241, and the button 233 b can extend through a differentcomplementary opening 229 formed in the housing 250, adjacent to theopening 231 and having a longitudinal axis that extends therethroughthat is substantially perpendicular to a longitudinal axis extendingthrough the opening 231. The rod 233 r sits within a channel 233 cformed in the button 233 b to loosely hold the button 233 b within thestructure of the housing 250. The opening 231 is formed so that it isaligned with the track 235 when the rotatable receiver is properlydisposed within the housing 250. A portion of a sidewall of the rod 233r extends through the opening 231 and into the opening 241, and thus canextend into the track 235. Such a configuration aids the rotatablereceiver 246 in being able to rotate with respect to the housing 250. Aspring 233 s can be disposed in the opening 229, between a base of theopening 229 and the button 233 b, to allow the button 233 b to floatwithin the opening 229, at least due in part to the loose hold the rod233 r has on the button 233 b. A force supplied by the spring 233 s tothe button 233 b can be large enough to hold the rotatable receiver 246in a locked position but small enough to allow the rotatable receiver tobe unlocked by rotating it in the opposite manner without using any sortof release button to disengage the button 233 b from the indent 246 i.

The opening 229 is formed so that a proximal end of the button 233 b canengage one of the indents 246 i formed in the rotatable receiver 246 tosecure the locking position of the rotatable receiver 246 with respectto the housing 250. As shown, the button 233 b includes a tapered ramp233 t at its proximal end that is complementary to the indents 246 i.When the ramp 233 engages the surface of the rotatable receiver 246 thatforms the indent 246 i, the rotatable receiver 246 can be secured in thelocking position, as shown in FIG. 10. As shown in the illustratedembodiment, one of the indents 246 i is a bit larger than the other, andit is the surface of the larger indent 246 i that engages the button 233b when the rotatable receiver 246 is in the locking position. Thesurface of the smaller indent 246 i engages the button 233 b when therotatable receiver 246 is in the receiving position, and thus preventsthe rotatable receiver from rotating past the receiving position. Theforce required to disengage the surface of the smaller indent 246 i fromthe button 233 b is less than the force required to disengage thesurface of the larger indent 246 i from the button 233 b.

The ramp 233 in the illustrated embodiment is configured such that itcan also serve as an offloading ramp that allows the rotatable receiver246 to be removed from the locking position when an opposing force inthe counter-clockwise direction is applied to the rotatable receiver 246sufficient to overcome the inertia created between the ramp 233 and thesurface forming the indent 246 i. Alternatively, because the button 233b floats within the opening 229, an alternative way by which therotatable receiver 246 can be removed from the locking position is bypushing the button 233 b towards the distal end 240 d to disengage thebutton 233 b from the surface that forms the indent 246 i.

The bullet-receiving opening or channel 242 formed in the rotatablereceiver 246 can extend from its proximal end 246 p to its distal end246 d. The opening 242 can be shaped in a variety of ways, but in theillustrated embodiment it has a substantially cylindrical shape that iscomplementary in shape to the bullet it is configured to receive. Asshown, it can be described as having a C-shape. Likewise, a diameter ofthe opening 242 is such that it is sized to receive a bullet therein. Inthe illustrated embodiment, a diameter of the bullet-receiving opening242 is approximately half the size of the diameter of the rotatablereceiver 246, thus resulting in the illustrated C-shape. The shape ofthe opening 242 formed in the rotatable receiver 246, along with thevarious features described herein to help secure a bullet within thebullet-receiving opening 242, allow a bullet to be inserted into theopening 242 from the side. More specifically, a bullet can be passedfrom an outside environment, across the plane P₁ extending substantiallythrough the first facial surface 250 f, and into the bullet-receivingopening 242.

The guide-receiving opening 244 extends substantially transverse to alongitudinal axis LA′ of the housing 250, and thus substantiallytransverse to the opening 242, and it extends through the housing fromand through the first side surface 250 r to and through the second sidesurface 250 s. As shown, the opening 244 can be defined by an inner wallof the proximal end 250 p, an inner wall of the distal end 250 d, aninner wall of the first facial surface 250 f, and an inner wall of thesecond facial surface 250 g, e.g., predominantly by an inner wall of theguide engaging mechanism 260. The guide-receiving opening 244 can extendin a different plane than the bullet-receiving opening 242. A size andshape of the guide-receiving opening 244 can be complementary to thesize and shape of the first arm 222 of the guide arm 220 such that thefirst arm 222 can extend through the guide-receiving opening 244 and thecarriage 244 can be securely locked at one or more locations along alength of the first arm. In the illustrated embodiment, a length L′ ofthe carriage 240 can extend substantially transverse to a length l′ ofthe first arm 222. As described above, as used herein the termsubstantially transverse does not necessarily mean exactly transverse,at least because of the arcuate configuration of the first arm 222. Aperson skilled in the art will understand that such a description isgenerally intended to address the fact that, as shown, the length L′ ofthe carriage 240 is not generally disposed in the same direction as thelength l′ of the first arm 222.

The guide engagement mechanism 260 that is configured to extend betweenthe upper and lower portions 250 a, 250 b to form the second facialsurface 250 g that also defines the guide-receiving opening 244 can beof a similar construction as discussed above with respect to the guideengagement mechanism 160, and thus can also serve as a passive engaginglocking mechanism. As shown, the guide engagement mechanism 260 caninclude a bar 262 that is opposed substantially parallel to the firstfacial surface 250 f, although not necessarily exactly parallel inembodiments in which the first facial surface 250 has a slight taperwith respect to the plane P₂ as described above. A proximal end 262 p ofthe bar 262 can be a button 266 configured to be pressed by the thumb ofa user. As shown, the button 266 includes gripping features formed on atop surface thereof to prevent a user's thumb from slipping off of thebutton. The portion of the proximal end 262 p below the gripping portioncan be sized to fit within an elongate opening 251 formed in the upperportion 250 a of the second facial surface 250 g.

An intermediate portion 262 i of the bar 262 can include a male member,as shown a selectively deployable key 264, and two openings 268, 269.The key 264 can have a shape and size that is complementary to a shapeand size of the female member formed on the arm guide, e.g., theplurality of slots 230, similar to the key 164 of the carriage 140. Thefirst opening 268 formed in the bar 262 can be for viewing indicia 232formed on the first arm 222, while the second opening 269 can be used inconjunction with a mechanism for selectively locking a bullet in a thirddimension, as described below.

Notably, when a bullet disposed in the carriage 240 is in theintermediate position or the locked position, it is prevented fromtranslating between the two side surfaces 250 r, 250 s and between thetwo facial surfaces 250 f, 250 g. However, the bullet is not necessarilyprevented from translating in a third dimensions, along the longitudinalaxis LA′. As described in greater detail below, when the carriage 240 isin the intermediate position, a bullet disposed therein can freelytranslate distally and proximally along the longitudinal axis LA′through the bullet-receiving opening 242, and when the carriage is inthe locking position, a bullet disposed therein can translate distallyalong the longitudinal axis LA′ through the bullet-receiving opening 242when a certain amount of force is applied to the bullet. In the lockingposition, when such threshold force is not exceeded however, then thecarriage 240 is configured to maintain the location of the bullet withrespect to the longitudinal axis LA′, i.e., the third dimension.

The second opening 269 is involved with locking the bullet in a thirddimension by being configured to receive a spring-loaded pin 253 that isoperable to maintain the location of a bullet disposed in thebullet-receiving opening 242 when a threshold force is not met orexceeded, but then allow the bullet to travel along the longitudinalaxis LA′ when the threshold force is met or exceeded. The spring-loadedpin 253 can be disposed in the second opening 269, through a centralopening 261 formed in the upper portion 250 a of the second facialsurface 250 g, and can extend into the elongate opening 251. As shown inFIG. 11, the spring-loaded pin 253 includes a housing 255 having aspring 257 disposed therein, and a translating distal tip or end cap259. The end cap 259 is biased by the spring 257 into the opening 242for receiving the rotatable receiver 246, and thus the bullet. When therotatable receiver 246 is in an open position to receive a bullet, theend cap 259 is biased out of the opening 242 by the outer surface of therotatable receiver 246. However, when the rotatable receiver 246 is inthe locking position, the end cap 259 can be biased into contact withthe bullet to help maintain a location of the bullet with respect to thecarriage 240 unless a threshold force applied to the bullet is met orexceeded, in which case the bullet can translate distally. In someembodiments, a proximal end 255 p of the housing can be threaded and canbe threadingly mated to threads disposed in the central opening 261.Such a configuration helps maintain a location of the pin 253 withrespect to the housing 250, and further, can allow a threshold force tobe changed. For example, rotating the housing 255 can increase ordecrease an amount of force applied to the spring 257, thereby adjustingthe threshold force of the pin 253.

As described below with respect to FIG. 12B, the distal end cap 259 cancontact engagement features formed on the bullet 270, such as ridges274, to help maintain the bullet 270 location in the absence ofapplication of the distally-applied threshold force. The interaction ofthe cap 259 and ridges 274 acts as a one-way locking mechanism thatprevents the bullet from being advanced proximally, but allows thebullet to advance distally in response to a force that meets or exceedsthe threshold force. More particularly, the ridges 274 can be angledsuch that they only allow for distal travel. When the threshold force ismet or exceeded, the bullet 270 will advance distally towards theintended location of the proximal end of the bone tunnel. The value ofthe threshold force can depend on a variety of factors, including butnot limited to the configurations of the carriage and bullet, and can beadjusted as described herein or otherwise known to those skilled in theart.

Springs 263 can be disposed in the elongate opening 251, configured tobias the button 266, and thus the key 264, proximally away from theproximal end 240 p of the carriage 240. The springs can be disposed onopposite sides of the bar 262 below the button 266. Similar to the guideengaging mechanism 160, the button 266 can be biased proximally suchthat the carriage 240 can freely translate along the guide arm 220,including over and past the slots 230 formed in the first arm 222, whenthe button 266 is depressed against the bias of the springs 263, and thekey 264 can passively engage the slots 230 to lock the location of thecarriage 240 with respect to the arm 222 when the button 266 is notdepressed.

A distal end 262 d of the bar 262 can include a ledge 265 such that athickness TL of the ledge is greater than a thickness T₁ of theintermediate portion. The ledge 265 can be configured to sit within anelongate opening 267 formed in the lower portion 250 b of the secondfacial surface 250 g and engage a portion of the lower portion 250 b tokeep the guide engaging mechanism 260 associated with the housing 250,i.e., it prevent the guide engaging mechanism 260 from falling out ofthe housing 250.

In some embodiments an identification plug 227 p can be provided in theupper portion 250 a of the second facial surface 250 g. As shown, theplug 227 p can be disposed in an opening 225 adjacent to the opening 261that receives the spring-loaded pin 253, and can be coupled to anidentification rod 227 r thereto. The identification rod 227 r can bedisposed in an opening 223 formed in the side surface 250 s of thehousing 250. The identification plug 227 p and identification rod 227 rcan help a surgeon easily identify the type of carriage, for instancebased on the color of the plug 227 p and the rod 227 r. As a result,during a surgery, the surgeon does not need to test the carriage to seeif it is a side-loading carriage or a top-loading carriage. The surgeoncan know based on the shape, configuration, and/or color of either orboth of the identification plug 227 p and identification rod 227 r.Other types of identifiers can also be included on the carriage for asimilar purpose, including but not limited to labels and/or color-codingof other components of the carriage.

A person having ordinary skill in the art will recognize a variety ofother configurations that can be used to form the carriage withoutdeparting from the spirit of the present disclosure. Bearing that inmind, in some embodiments, such as the carriages 140 and 240 illustratedherein, a length L, L′ of the carriage 140, 240 can be in the range ofabout 2 centimeters to about 6 centimeters, a width W, W′ of thecarriage 140, 240 can be in the range of about 1 centimeters to about 5centimeters, and a thickness T, T′ of the carriage 140, 240 can be inthe range of about 1 centimeters to about 6 centimeters. In oneexemplary embodiment for each of the carriages 140, 240 they have alength L, L′ of about 4 centimeters, a width W, W′ of about 3centimeters, and a thickness T, T′ of about 3 centimeters. A personhaving ordinary skill in the art would be able to derive suitabledimensions for components of the carriage, e.g., the guide engagementmechanism, the rotatable receiver, etc., in view of these dimensions,the dimensions of the components associated therewith, and the otherdisclosures provided for herein or otherwise known in the art. Thecarriage and related components can be made from a variety of materials,including but not limited to surgical grade metals such as stainlesssteel and titanium or various polymers. Some features, e.g., thegripping portion of the button, can be configured to be made fromsuitable materials known to those skilled in the art. Accordingly, acomponent such as the gripping portion can be made from rubber or othersuitable material suitable for providing enhancing a user's grip.

Bullet

A bullet for use in conjunction with the arm guides and carriagesprovided for herein can have a variety of configurations, depending, atleast in part, on the configurations of the arm guide, carriage, andother components with which the bullet is being used, the anatomy of thepatient, and the type of procedure being performed. In the illustratedembodiment of FIGS. 12A and 12B, the bullet 270 is an elongate andsubstantially cylindrical or tubular shaft 271 having a proximal end 270p, a distal tip or end 270 d, and an intermediate portion or length 270i extending therebetween. The bullet 270 is cannulated across anentirety of its length, as shown by bore 272, so that a drillingcomponent, such as a drill pin and/or reamer, can be passed through thebullet and to the bone in which the bone tunnel is to be formed.

The proximal end 270 p can have a face 270 f configured to engage with adistal end of a drill. As shown, the face 270 f has a substantiallytriangular shape and has an outer-facing surface that is concave. Theconcavity of the face 270 f can assist in directing instruments into thebullet 270. Although not visible because of an identifier 274 disposedaround an outer surface of the shaft 271, the face 270 f can beunitarily formed with the shaft 271 such that the face 270 f is anextension of the shaft 271. In other embodiments, the face 270 f can beremovably and replaceably attached to the shaft 271 so that differentlyconfigured faces can be used with a single bullet shaft 271. In theillustrated embodiment, an identifier 274 is disposed around the shaft271, proximate to the face 270 f The identifier 274 can help identify abullet type, as a person skilled in the art will recognize that bulletscan be optimized for certain uses. By way of non-limiting example, somebullets may be more conducive for use with drill pins while anotherbullet may be more conducive for user with reamers. In otherembodiments, no such identifier 274 is used.

As shown, the shaft 271 at the distal end 270 d can become tapered, forinstance by varying a thickness of a wall of the shaft 271, to make iteasier to push the bullet 270 through tissue so it can be seated againstthe bone. In some embodiments, bone engaging features, as shown teeth270 t, can be formed at the terminal end of the distal end 270 d. Theteeth 270 t help the distal end 270 d stabilize the location of thebullet 270 with respect to the bone. The stabilization can help providemore accurate measurements when using the bullet 270 to determine thesize of the bone stock, and more accurate drilling when drill pins andreamers are being passed through the bullet 270 and into the bone toform the bone tunnel.

The intermediate portion 270 i can have a groove or channel 276 formedon one side thereof and contact engagement features, as shown ridges278, on another side thereof. As shown, the groove 276 extends along alength of the intermediate portion 270 i and is configured to be engagedby a protrusion extending from a surface that forms the bullet-receivingopening, whether that opening is formed in the housing itself or in therotatable receiver disposed in the housing, e.g., the protrusion beingthe pin 239 extending into the bullet-receiving opening 246. The deepestportion of the groove 276 can extend far enough into the outer surfaceof the bullet 270 that the bullet 270 can be disposed in a lockedposition when the groove 276 is engaged by the protrusion, but not sodeep that the groove 276 passes into the bore 272 that forms thecannulated configuration of the bullet 270. By not disposing the groove276 that deep, the bullet 270 can be held in an intermediate lockingposition without falling out of the carriage, as described in greaterdetail elsewhere. While in some embodiments the groove 276 can extendinto the bore 272, such a configuration would make it easier for acomponent such as a drill pin passing through the bullet 270 tounexpectedly pass out of the bore 272 and the groove 276 and to anoutside environment. The length of the groove 276 can vary depending ona variety of factors, and thus the illustrated length by no means limitsthe length or location of the groove. The length of the groove 276 isgenerally as long as or longer than the desired distance of longitudinaltravel for the bullet 270. Otherwise, the pin 239 or related componentwould not be engaged with the groove 276 at all times as the bullet 270translates along the longitudinal axis LA′ of the housing 250, whichwould in turn lead to a less secure hold of the bullet 270 in use. Inembodiments in which the pin 239 is not involved, such as the embodimentof FIGS. 17A-20B, this is obviously not a concern.

The ridges 278 formed in the outer surface of the intermediate portion270 i can extend across at least a portion of the length of the bullet270. The ridges 278 can be configured to receive the distal tip 259 ofthe spring-loaded pin 253 that is configured to selectively engage thebullet 270 to temporarily maintain the location of the bullet withrespect to the carriage 240. Further, the ridges 278 can be disposed atan angle such that when the bullet 270 is in the locked position and thecarriage 240 are in the locking position, the bullet 270 can only beadvanced distally along the longitudinal axis LA′, and not proximallyalong the longitudinal axis LA′. More particularly, when the thresholdforce applied in a direction J is exceeded, the distal tip 259 canretract to allow the bullet 270 to advance along the longitudinal axisLA′ until the force applied again falls below the threshold force, atwhich point the distal tip 259 engages a ridge 278 and maintains thelocation of the bullet 270 with respect to the carriage 240 at the newlocation. The interaction of the distal tip 259 and the ridges 278 canbe audible such that as the bullet 270 advances or retracts, the distaltip 259 makes noise as it drags along the ridges 278 while the thresholdforce is overcome. Further, as the force applied falls below thethreshold force or is removed all together, a clicking noise can beheard as the distal tip 259 fully engages the ridge 278 to secure thenew location. Similar to the length of the groove 276, the length of theridged portion can generally be as long as or longer than the desireddistance of longitudinal travel for the bullet 270 to insure that thedistal tip 259 can remain engaged with the bullet 270 at any desiredlocation of the bullet 270 with respect to the carriage 240.

In some embodiments, such as the bullet 170 illustrated in FIG. 15,indicia 177 can be formed on an intermediate portion 170 i to assist auser in identifying the distance traveled by the bullet and/oridentifying a size of a bone stock, as described in greater detailbelow.

A person having ordinary skill in the art will recognize a variety ofother configurations that can be used to form the bullet withoutdeparting from the spirit of the present disclosure. In some exemplaryembodiments, a length of the bullet can be in the range of about 10centimeters to about 20 centimeters, and a diameter of the bullet can bein the range of about 4 millimeters to about 8 millimeters. In oneexemplary embodiment, a length of the bullet is about 14 centimeters anda diameter of the bullet is about 7 millimeters. The bullet can be madefrom a variety of materials, including but not limited to surgical grademetals such as stainless steel and titanium or various biocompatiblepolymers.

Carriage and Bullet

FIG. 13 illustrates the bullet 270 disposed in the carriage 240 with therotatable receiver 246 being in the locking position, and thus thebullet being in the locked position. As shown, in the locked positionthe bullet 270 is unable to translate between the first and secondfacial surfaces 250 f, 250 g, and is also unable to translate betweenthe first and second sidewalls 250 r, 250 s. When the carriage 240 isdisposed on the guide arm 220, as shown in FIG. 3, then the bullet 270,by way of the carriage 240, can translate in a direction substantiallyparallel to the direction extending between the first and secondsidewalls 250 r, 250 s, i.e., along the length of the first arm 222. Asshown in FIG. 3, when the carriage 240 is disposed on the guide arm 220,the first and second facial surfaces 250 f, 250 g of the carriage 240and the first and second facial surfaces 222 f, 222 g of the first arm222 are substantially parallel, which as indicated above does notnecessarily mean exactly parallel in view of possible taperedconfigurations of at least the facial surfaces 250 f and 250 g. Moreparticularly, the first facial surface 250 f extends away from the firstfacial surface 222 f, and is located closer to the first facial surface222 f than the second facial surface 222 g. Likewise, the second facialsurface 250 extends away from the second facial surface 222 g, and islocated closer to the second facial surface 222 g than the first facialsurface 222 f.

In the locked position the bullet 270 is able to translate distallyalong the longitudinal axis LA′ of the housing 250. More particularly,when a force applied to the bullet 270 in the distal direction J exceedsthe threshold force supplied by the distal tip 259, the bullet 270advances in the direction J until the force applied no longer exceedsthe threshold force. When the threshold force is exceeded, the distaltip 259 bias is overcome and thus the distal tip 259 is pushed backtowards the second facial surface 250 g by each ridge 278. When thethreshold force is no longer exceeded, the distal tip 259 is biased backinto engagement with a ridge 278, i.e., towards the first facial surface250 f, and helps secure the location of the bullet 270 with respect tothe rotatable receiver 246 and housing 250.

FIG. 14 illustrates an alternative embodiment of a side-loading carriage240′ having a rotatable receiver 246′ with a bullet-receiving opening242′, the side-loading carriage 240′ being disposed on the first arm 122of the guide arm 120. The housing 250′, rotatable receiver 246′, andguide engaging mechanism 260′ have many of the same features describedabove with respect to the side-loading carriage 240. For example, therotatable receiver 246′ is associated with a first facial surface 250 fsuch that when the rotatable receiver 246′ is in a receiving position,the bullet-receiving opening 242′ extends towards an outsideenvironment, and when the rotatable receiver 246′ is in a lockingposition, the bullet-receiving opening 242′ faces a second facialsurface 250 g′ (not shown) and secures the bullet in the locked positionin which the bullet is locked in at least two planes as described above.One difference, however, is that the ramp (not shown) disposed in thehousing 250′ at a location similar to the ramp 233 for the housing 250is not configured to allow for the rotatable receiver 246′ to bedisengaged from the locking position by rotating the rotatable receiver246′ in a direction opposite to the direction it was rotated to put itin the locking position. Instead, the button 233 b′ must be depressed torelease the rotatable receiver 246′ from the locking position. As shown,the button 233 b′ protrudes proximally away from the outer surface ofthe proximal end 250 p′, and another portion of the button 233 b′ (notvisible) engages a surface that forms an indent 246 i′ in the proximalend 246 p′ of the rotatable receiver 246′ to hold the rotatable receiver246 in the locking position. The button 233 b′ can be depressed towardsthe distal end 250 d′ to disengage the portion of the button 233 b′ thatengages the surface that forms the indent 246 i′ so that the rotatablereceiver 246′ can be moved out of the locking position and towards thereceiving position. As shown, both a button 266′ of the guide engagingmechanism 260′ and the button 233 b′ can include a grip formed thereon,e.g., made of rubber or other suitable material, to assist a user ingripping the respective buttons.

The carriage of FIG. 14 can be configured to be used with a bullet ofthe nature illustrated in FIG. 15. The bullet 170 is similar to thebullet 270 of FIGS. 12A and 12B, and thus only a proximal portion 170 pand intermediate portion 170 i are illustrated. As shown, the proximalportion 170 p, including its face 170 f, has a unitary construction withthe intermediate portion 170 i. Further, the intermediate portion 170 iincludes indicia 177 formed thereon. The indicia can be formed anywherealong the circumference of the outer surface of the bullet 170, and thusin the illustrated embodiment the indicia are formed adjacent to thegroove 176. The indicia 177 illustrated on the bullet 170 are such thatthe number values decrease the more proximally disposed the value is,with each marking being five millimeters apart from the next one. Theindicia 177 can be used to identify a size of the bone stock, i.e., thethickness of the bone to be drilled through and thus the length of thebone tunnel to be drilled. More particularly, as the bullet 170 isadvanced distally toward the bone, the values visible to the userdecrease because the more distally located values become hidden by acarriage in which the bullet is disposed. Once the distal tip of thebullet 170 contacts the bone to be drilled, with the distal tip 126 ofthe second arm 124 of the guide 110 being located at the desired distalend of the bone tunnel to be drilled, the bone stock is the value stillvisible, adjacent to the carriage 140.

FIGS. 16A-16C illustrate how the bullet 170 can be inserted into aside-loading carriage like the carriage 240′ and subsequently removed.In the illustrated embodiment, the carriage 240′ is disposed on the arm120, forming a surgical guide 210′. In FIG. 16A, the bullet 170 has beeninserted into the bullet-receiving opening 242′ of the rotatablereceiver 246′ by passing it across the plane P₁ extending substantiallythrough the first facial surface 250 f. The bullet 170 is then rotatedin a clockwise direction T until the protrusion (not shown) extendingfrom the rotatable receiver 246′ enters the groove 176 formed in thebullet 170. This places the bullet in its locked position in which thebullet 170 is unable to translate between the two facial surfaces 250 f,250 g′ or the two side surfaces 250 r′, 250 s′ of the carriage 240′.Further, once the bullet 170 is in the locked position, any furthertorque applied to the bullet 170 in the direction T is also applied tothe rotatable receiver 246′ so that both the bullet 170 and therotatable receiver 246′ rotate in the clockwise direction T. This movesthe rotatable receiver 246′ from the receiving position, in which theopening 242′ is fully exposed to the outside environment to receive thebullet, and towards the locking position. In the locking position, therotatable receiver 246′ does not rotate in response to the same amountof torque that is applied in the direction T and the bullet 170 remainsin its locked position. As described elsewhere herein, a button 266′associated with the guide engaging mechanism 260′ can be depressed toallow the carriage 240′, and thus the bullet disposed therein 170, totranslate and selectively lock along a length of the first arm 122.

FIG. 16B illustrates the rotatable receiver 246′ advancing towards thelocking position, also referred to as an intermediate position, whileFIG. 16C illustrates the rotatable receiver 246′ in the lockingposition. In the intermediate position, the bullet 170 is received bythe rotatable receiver 246′ and is able to freely translatedback-and-forth between the two sides 250 r′, 250 s′.

As shown in FIG. 16C, in the locking position the rotatable receiver246′ has rotated approximately 180 degrees from the receiving positionsuch that the bullet-receiving opening 242′ faces towards the secondfacial surface 250 g′ instead of towards the outside environment. Therotatable receiver 246′, and thus the bullet 170, are maintained at thislocation by a ramp 233′ (not shown) disposed within the opening 241′(not shown) of the carriage 240′ that receives the rotatable receiver246′. The ramp 233′ engages first the groove 235′ and then the surfacethat forms the indent 246 i′ (not shown) in the proximal end 246 p′ ofthe rotatable receiver 246′, thereby holding the rotatable receiver 246′in the locking position. In this position, the bullet 170 can stilltranslate along the longitudinal axis LA″ of the housing 250′ such thatthe distal tip 170 d can be advanced towards the distal end 250 d′ inthe direction J. For example, the distal tip 170 d of the bullet 170 cantranslated distally until it contacts the bone. In such a position, thebullet 170 can be used to measure a bone stock, guide a drill pin orother drilling components into the bone for forming the bone tunnel, orbe used as a guide for other instruments to be passed through a bonetunnel once the bone tunnel is formed.

The bullet 170 can be removed from the carriage 240′ by pushing therelease button 233 b′ down so that the surface that forms the indent 246i′ is no longer engaged by the ramp 233′ associated with the button 233b′. As a result, when a counter-clockwise torque U is applied to thebullet 170, both the bullet 170 and the rotatable receiver 246′ canrotate in the counter-clockwise direction U back towards the initial,receiving position of the rotatable receiver 246′, i.e., where thebullet-receiving opening 242′ is exposed to the outside environment toreceive a bullet therein. As discussed elsewhere herein, in otherembodiments the configuration of the carriage can be such that rotationin the opposite direction U is sufficient to move the rotatable receiverfrom its locking position without pressing a release button like thebutton 233 b′.

Once the rotatable receiver 246′ is returned to its initial, receivingposition, the bullet 170 can be removed from the carriage 240′ bypassing it back across the plane P₁. The groove 176 of the bullet 170becomes disengaged from the protrusion of the rotatable receiver 246′just by advancing the bullet 176 across the plane P₁ because thedirection the bullet 170 is advanced to cross the plane P₁ is directlyaway from the protrusion. Alternatively, the bullet 170 can be passedout of the carriage 240′ by pulling it proximally in a direction K untilit is removed from the bullet-receiving opening 242′. However, this canbe less advantageous because often times a drill pin or other drillingcomponent is disposed in the bullet 170, and thus the drill pin or otherdrilling component must be long enough to allow the bullet 170 to movefully out of the opening 242′ while the drill pin or other drillingcomponent remains extended through the formed bone tunnel. As a result,the drill pin or other drilling component must be long enough to extendfully through the bone tunnel and proximally beyond the guide 210′ sothat the bullet 170 stays associated with the drill pin or otherdrilling component when it passes out of the opening 242′. This lengthis significantly longer than the length just needed to form the tunnel,significantly increase the likelihood of divergence. By passing thebullet 170 out of the side of the carriage, across the plane P₁, thedrill pin does not need to have the extra length to account fordisassociation of the bullet 170 from the guide 210′.

In some exemplary embodiments, after at least a pilot hole of the bonetunnel has been drilled, thereby defining a path for the full formationof the bone tunnel and eventual location of a graft ligament, the bullet170 can be disassociated from the carriage 240′ and the carriage 240′and arm 120 removed from the surgical site while the bullet to providefurther guidance for any instruments being used at the surgical site,e.g., a retrograde reamer being passed back through the pilot hole toform the full bone tunnel.

Further Side Loading Carriage and Bullet Embodiment

FIGS. 17A-17C, 18, and 19 illustrate another alternative embodiment of aside loading carriage 340, and FIGS. 20A and 20B illustrate anotheralternative embodiment of a bullet 370 that is configured to be usedwith the side-loading carriage 340. The configuration of the carriage340 is similar to the carriage 240, and thus this embodiment isdescribed with an intention of highlighting the differences between thetwo carriages. The carriage 340 and bullet 370 can be used inconjunction with the guide arms provided for herein, derivable from thepresent disclosures, or otherwise known to those skilled in the art.

The carriage 340 includes a housing 350 that can have many differentshapes and sizes, which can depend, at least in part, on theconfiguration of the device components with which it is being used, theanatomy of the patient, and the type of procedure with which it is beingused. Similar to the housing 250 of the carriage 240, the housing 350has the shape of a trapezoidal prism that includes a proximal end 350 p,a distal end 350 d, two opposed facial surfaces 350 f, 350 g extendingbetween the proximal and distal ends 350 p, 350 d, and two opposed sidesurfaces 350 r, 350 s extending between the two facial surfaces 350 f,350 g and the proximal and distal ends 350 p, 350 d. Again, similar tothe housing 250, each of the identified surfaces need not be continuous,e.g., the second facial surface 350 g can include an upper portion 350 aand a lower portion 350 b that are not continuous, and a portion of aguide engaging mechanism 360, as shown an outer surface 360 g, canextend between the two portions 350 a, 350 b to form a wall of aguide-receiving opening 344 that extends through the housing 350 fromone side surface 350 r to the other side surface 350 s. A length L″, awidth W″, and a thickness T″ of the housing 350 can be defined by thesame distances described above with respect to the housing 250, and asillustrated in FIGS. 21A-21C and 22. Typically the length L″ is greaterthan the width W″ and the thickness T″. As shown in FIG. 17B, the secondfacial surface 350 g of the top portion 350 a tapers away from a centralportion of the surface 350 g such that the width W″ gets smaller towardsthe proximal surface 350 p. Likewise, as also shown in FIG. 17B, thesecond facial surface 350 g of the bottom portion 350 tapers away from acentral portion of the surface 350 g such that the width W″ gets smallertowards the distal surface 350 d.

The carriage 340 also includes a bullet-receiving opening 342 and aguide-receiving opening 344. More particularly, the bullet-receivingopening 342 is formed within a rotatable receiver 346, which isrotatably disposed within the housing 350. An opening 341 can be formedin the first facial surface 350 f to receive the rotatable receiver 346,and can include a main receiving portion 341 m and a track portion 341 tformed in the proximal end 350 p of the housing 350.

While the rotatable receiver 346 generally has the same construction andfunctionality as the rotatable receiver 246, the receiver 346 isdifferent in at least two significant ways. First, the bullet-receivingopening 342 is shaped differently. As shown, the opening 342 issubstantially U-shaped such that opposed sides 342 a, 342 b aresubstantially flat, and a curved side 342 c extends between the twosides 342 a, 342 b. This shape is complementary to the shape of thebullet 370 illustrated in FIGS. 20A and 20B, and helps to lock thebullet into the rotatable receiver 346 such that the bullet is in theintermediate position and subsequently the locked position. In thatregard, the rotatable receiver 346 also does not include a pin, such asthe pin 239, to assist in securing a location of the bullet with respectto the rotatable receiver. The lack of a pin 239 or similar securingmechanism is the second significant difference between the rotatablereceivers 246, 346, and thus the carriages 240, 340.

In the illustrated embodiment, a diameter of the bullet-receivingopening 342 is approximately half the size of the diameter of therotatable receiver 346, thus resulting in the illustrated U-shape. Whilethe shape of the opening 342 is different than the opening 242, it issimilar to the opening 242 in that its configuration allows a bullet tobe inserted into the opening 342 from the side. More specifically, abullet can be passed from an outside environment, across the plane P₁′extending substantially through the first facial surface 350 f, and intothe bullet-receiving opening 342.

Other features of the rotatable receiver 346, including but not limitedto the distal end 346 d, the main body 346 m, the proximal end 346 p,the opposed indents 346 i, and the track 335, can be included as part ofthe rotatable receiver 346 and can operate and be configured in asimilar manner as the like-numbered components of the rotatable receiver246. Likewise, other features of the carriage 340 more generally,including but not limited to the guide engagement mechanism 360, and itsbar 362, key 364, ledge 365, button 366, and openings 368, 369, springs363 for biasing the guide engagement mechanism 360, the spring-loadedpin 353 for engaging a bullet disposed in the rotatable receiver 346,and the pin's housing 355, spring 357, and distal tip 359, and the ramp333, and its components rod 333 r, button 333 b, and spring 333 s, aswell as openings that receive the various components of the carriage340, such as the guide-receiving opening 344, the elongate openings 351,367 for receiving the guide-engagement mechanism 360, and openings 331and 329 for receiving portions of the ramp 333, can be included as partof the carriage 340 and can operate and be configured in a similarmanner as the like-numbered components and openings of the carriage 240.The carriage 340 does not include the equivalent of an identificationplug 227 p or rod 227 r, which is at least a third difference betweenthe carriage 340 and the carriage 240.

In use, the rotatable receiver 346 generally operates similar to therotatable receiver 246, and thus the receiver 346 rotates with respectto the housing 350 between a first, receiving position and a second,locking position, which is illustrated in FIGS. 17A-17C and 18. Therotatable receiver also provides for the aforementioned intermediateposition in which a bullet disposed therein can translate freely along alongitudinal axis LA′″ extending through the opening 342. Further, theexemplary carriage widths, lengths, thicknesses, and materials providedfor above with respect to the carriages 140, 240 are equally applicableto the carriage 340.

The configuration of the carriage bullet 370 is similar to the bullet270, and thus this embodiment is described with an intention ofhighlighting the differences between the two bullets. In the illustratedembodiment of FIGS. 20A and 20B, the bullet 370 is an elongate andsubstantially cylindrical or tubular shaft 371 having a proximal end 370p, a tapered distal tip or end 370 d, and an intermediate portion orlength 370 i extending therebetween. The bullet 370 is cannulated acrossan entirety of its length, as shown by bore 372, so that a drillingcomponent, such as a drill pin and/or reamer, can be passed through thebullet and to the bone in which the bone tunnel is to be formed. Whilethe bullet 370 can be described as being substantially cylindrical ortubular, the shaft 371 is shaped differently than the shaft 271. Asshown, the shaft 371 includes two opposed curved portions 371 c, and twoopposed flat portions 371 f. The two opposed flat portions 371 f areconfigured to engage with the flat portions 342 a, 342 b of thebullet-receiving opening 342 of the carriage 340 to secure the bullet370 within the carriage 340 and lock the bullet in two planes such thatthe bullet cannot translate between the first and second facial surfaces350 f, 350 g or between the first and second side surfaces 350 r, 350 s.

The configuration of the proximal end 370 p is one way by which thebullet 370 differs from the bullet 270. The proximal end 370 p has amore elongate construction, including opposed arms 370 a and 370 b,which is more conducive to rotating the bullet 370. The additionallength of the opposed arms 370 a, 370 b allow a user more leverage whenproviding a rotational force to the bullet 370, and are also easier tofind and grip during the course of a surgical procedure. Similar to theproximal end 2′70 p, the proximal end 3′70 p does include a concaveportion 370 f disposed around the bore 372 that can assist in directinginstruments into the bullet 370.

The intermediate portion 370 i is different from the intermediateportion 270 i in at least two different ways. First, there is noequivalent groove or channel 276 formed in the intermediate portion 370i. This is because the carriage 340 does not include the equivalent pin239 to be received by the carriage. The lack of a groove or channel alsoallows for the second difference, which is that the engagement features,as shown ridges 378, can be disposed on opposed sides 371 c of theintermediate portion 370, with indicia 377 formed on the two otheropposed sides 371 f to assist a user in identifying the distancetraveled by the bullet and/or identifying a size of a bone stock. Theridges 378 can be similarly constructed as the ridges 278, and thus theycan be angled to allow for only distal advancement of the bullet 370along the longitudinal axis LA′″ when the bullet is disposed in thelocked position in the carriage 340. The illustrated embodiment, likethe other carriage and bullet embodiments, does not permit advancementof the bullet 370 proximally when the carriage 340 is in the lockingposition and the bullet 370 is in the locked position. Further, theexemplary bullet widths, lengths, thicknesses, and materials providedfor above with respect to the bullets 170, 270 are equally applicable tothe bullet 370.

Drill Pin Depth Gage

FIGS. 21A-21D illustrate one exemplary embodiment of a drill pin depthgage 380. A drill pin depth gage 380 can be used to help set a maximumdistance of travel for a drill pin that forms a bone tunnel in bone,sometimes referred to as a terminal distal travel location, so that thedrill pin does not travel further than desired and caused undesirabledamage to surrounding tissue. In some embodiments the bone tunnel can bea pilot hole that is later expanded, for instance using a reamer orretrograde reamer. The gages 380, 480 provided for herein can be used inconjunction with the devices, systems, and methods provided for herein,e.g., modular guides and bullets, as well as in conjunction with otherdevices, systems, and methods with which a drill pin is used to form abone tunnel.

The drill pin depth gage 380 generally includes an elongate shaft orguide tube 382 and an indicator 390. The indicator 390 can be configuredto be move along a length of the shaft 382 and selectively engage theshaft 382 to lock a location of the indicator 390 with respect to theshaft 382 to indicate a particular maximum length or distance. The gage380 can then be used in conjunction with a drill to chuck a drill pin tothe drill, thereby setting the maximum travel distance for that drillpin.

Shaft

As shown, the elongate shaft 382 is substantially cylindrical and has abore or channel 384 extending through a substantial length thereof. Thechannel 384 extends from a proximal end 382 p and towards a distal end382 d of the shaft 382 and is configured to have a drill pin disposedtherein. A proximal portion 384 p of the channel 384 can have a diameterthat is larger than the rest of the channel 384 to provide a largerreceiving region to insert the drill pin into the channel 384. Thislarger diameter can also help allow the gage 380 to sit flush againstthe chuck of the drill so that true measurements can be made and reliedupon when chucking the drill pin to the drill. While the channel 384 canbe extended all the way through the shaft 382, in the illustratedexemplary embodiment only one end is open to clearly delineate to theuser the end from which the measurement should be made, i.e., theproximal end 382 p.

Indicia 386 can be formed on an outer surface of the shaft 382 toindicate measured bone stock lengths. In particular, the indicia 386formed on the shaft 382 can correlate to bone stocks measured at thesurgical site. Thus, in some embodiments, the indicia 386 formed on thegage 380 can be the same indicia formed on the bullet such that ameasurement of bone stock made by the bullet can be used in conjunctionwith the gage 380 to set the same measurement on the gage 380, as willbe discussed in greater detail below.

In the illustrated embodiment, the indicia 386 are formed more proximateto the distal end 382 d than the proximal end 382 p, with the largestbone stock value being located most distal and the values decreasing asthe indicia 386 extend proximally. The values of the indicia 386 canhave a range of values, depending, at least in part, on the anatomy ofthe patient and the type of procedure being performed, but in theillustrated embodiment the values begin at 20 millimeters and extend to70 millimeters, increasing in increments of 5 millimeters. Further, inthe illustrated embodiment the indicia 386 are lines that extendapproximately half of the circumference of the shaft 382 with valuesdisposed directly below their corresponding lines, although any otherconfiguration for forming indicia on a device can also be used withoutdeparting from the spirit of the present disclosure.

Engagement grooves 388 can also be formed on the outer surface of theshaft 382. The engagement grooves 388 can be configured to be engaged bya portion of the indicator 390 to allow the indicator 390 to lock at alocation along the shaft 382. As shown, the engagement grooves 388 areformed closer to the distal end 382 d than the proximal end 382 p, atapproximately the same location along a length of the shaft 382 as theindicia 386. This allows the grooves 388 to be engaged by the indicator390 in conjunction with identifying the relevant bone stock value. Insome embodiments, the number of grooves 388 can be equal to the numberof values or marks of indicia 386 such that each groove is associatedwith one value or mark, but in the illustrated embodiment there are moregrooves than marks, which allows for bone stock measurements that fallin between the marks of the indicia 386 to be indicated on the shaft 382by the indicator 390. Further, in the illustrated embodiment the grooves388 have a length that is greater than half the circumference of theshaft 382, which is why the grooves can be seen in each of the FIGS.21B-21D views, although the grooves 388 can have any length or shapesuitable for engagement by the indicator 390. The size and shape of thegrooves can depend, at least in part, on the configuration of theindicator with which the shaft is being used.

The shaft 382 itself can have a variety of shapes and sizes, depending,at least in part, on the configuration of the indicator 390, drill pin,or other components with which it is used and the type of procedurebeing performed, but in the illustrated embodiment the shaft 382 has alength approximately in the range of about 10 centimeters to about 40centimeters, and a diameter approximately in the range of about 5millimeters to about 15 millimeters, and in one embodiment the length ofthe shaft is about 23 centimeters and the diameter of the shaft is about8 millimeters. Any number of materials can be used to form the shaft,including but not limited to surgical grade stainless steel, titanium,and polymers.

Indicator

The indicator 390 is configured to be complementary to the shaft 382 sothat the indicator 390 can easily translate along a length of the shaft382 and be locked at a location along the length to set the maximumlength of distance for the drill pin. The indicator 390 is illustratedwith some particularity in FIGS. 22A-22D. While the indicator 390 canhave a variety of shapes and sizes, in the illustrated embodiment theindicator 390 has a substantially cylindrical housing 392 with aproximal end face 392 p, a distal end face 392 d, a cylindrical sidewall392 s extending between the two faces 392 p and 392 d, and a centralopening 392 c extending from the proximal end face 392 p and through thedistal end face 392 d to allow the shaft 382 to pass therethrough. Asshown in the illustrated embodiment, the sidewall 392 s can be concavearound a circumference of the indicator 390 to make it easier for a userto grip or hold the indicator 390 and move it along the shaft 382. Oneor more finger grooves 393 can also be formed in the sidewall 392 s forfurther gripping benefits. As shown, two finger grooves 393 are formedon opposed sides of the sidewall 392 s, and a third finger groove 393 isformed on an opposite side of a button 394. The functionality of thebutton 394 is described below with respect to a groove engaging feature396.

A key 398 can extend from an inner wall 390 i of the indicator 390 thatforms the central opening 392 c. The key 398 can be sized and configuredto be received in the channel 384 formed in the shaft 382. This allowsthe indicator 390 to be translated along a length of the shaft 382without rotating a significant amount with respect to a centrallongitudinal axis LA, of the shaft 382, and while maintaining a closerelationship with the shaft 382. As shown, the key 398 can have arectangular cross section with a tapered upper surface 398 t. Any othernumber of configurations can be used to form the key 398 provided thatthe configuration is complementary to the configuration of the channel384 of the shaft 382. Further, while in the illustrated embodiment thekey 398 is disposed closer to the distal face 392 d than the proximalface 392 p, in other embodiments the key 398 can be disposedapproximately equidistant from the two faces 392 p, 392 d, or closer tothe proximal face 392 p.

A selectively deployable groove engaging feature 396 can also beprovided as part of the indicator 390. While a variety of configurationscan be used to selectively lock a location of the indicator 390 withrespect to the shaft 382 by engaging the grooves 388, in the illustratedembodiment the groove engaging feature 396 includes a translatable block397 disposed within the indicator 390. The block 397 can include anopening 397 b formed therein with an inner wall 397 w of the opening 397b disposed opposite from the button 394 being configured to selectivelysit within a groove of the grooves 388 when the block 397 is in thelocked position. The block 397 can be biased in the locked position, forinstance by a spring 395 disposed at a second end 397 d of the block 397that bias the block in a direction C, radially away from the shaft 382.A button 394 disposed at a first end 39′7 p of the block 397 can beoperated by a user to counteract the bias of the spring 395, therebymoving the block 397 from the locked position to a translating position.FIG. 22D illustrates the block 397, and thus the indicator 390, in thetranslating position. As shown, a force applied to the button 394 in adirection D, radially towards the shaft 382, translates the block 397radially towards the finger groove 393 that is opposed to the button394, and thus moves the inner wall 397 w in the same direction. In use,such movement disengages the inner wall 397 w from the grooves 388formed in the shaft 382, and thus allows the indicator 390 to translatealong a length of the shaft 382. When a force applied to the button 394is no longer sufficient to overcome the biasing force supplied by thespring 395, the block 397 radially advances in the direction C and isable to engage the a groove of the grooves 388 with the inner wall 397 wto establish a locked position.

A pin 399 can be disposed within the indicator 390 to prevent the block397 from falling out of the indicator 390. As shown, the pin 399 sitswithin a groove 397 g formed in an outer wall of the block 397, andengages one end wall 397 e of that groove 397 g when the indicator 390is in the translating position. The pin 397 g can be configured toengage an opposed end wall 397 f of the groove 397 g when the indicatoris in the locked position. In other embodiments, the pin 399 does notnecessarily engage end walls 397 f, 397 g when in either or both of thetranslating or locked positions.

The location of the button 394 and the inner wall 397 w thereof candepend, at least in part, on the configuration of the shaft 382 alongwhich the indicator 390 is configured to translate and the location ofother components of the indicator, such as the key 398. In theillustrated embodiment, when viewing a location of the button 394, theinner wall 397 w, and the key 398 from a perspective of the inner wall390 i, the button 394 and the inner wall 397 w are opposed from eachother, about 180 degrees around the inner wall 390 i from each other,while the key 398 sits about 110 degrees from each of the inner wall 397w and the button 394.

The indicator 390, and the components thereof, can have a variety ofshapes and sizes, depending, at least in part, on the configuration ofthe shaft 382, drill pin, or other components with which it is used andthe type of procedure being performed, but in the illustrated embodimentthe indicator has a diameter approximately in the range of about 0.5centimeters to about 5 centimeters, and a height H approximately in therange of about 5 millimeters to about 20 millimeters, and in oneembodiment the diameter of the indicator is about Z centimeters and theheight H is about 12 millimeters. Any number of materials can be used toform the indicator, including but not limited to surgical gradestainless steel, titanium, and polymers. The indicator 390 can, but doesnot have to, be made from the same material as the shaft 382.

Use of the Drill Pin Depth Gage and a Modular Guide

When the indicator 390 is coupled to the shaft 382, they can be used toassociate a measured bone stock with a drill pin such that a length ofthe drill pin extending from a drill is no longer than necessary to formthe bone tunnel in bone. This prevents the drill pin from passingthrough the bone after forming the distal end of the bone tunnel andcontacting tendons or other tissue and causing undesirable damage to thesame. In the illustrated embodiment, the proximal face 392 p of theindicator 390 is configured to be aligned with the value or mark of theindicia 386 that is the bone stock measurement. As a result, when adrill pin is disposed in the channel 384 of the shaft 382, the distaltip of the drill pin can abut the proximal face 392 p, setting that asthe maximum distance of travel for the drill pin. A drill pin can thenbe chucked at its proximal end such that a distal portion of the drillabuts the proximal end 382 p of the shaft 382. This results in aconfiguration in which the length of the bone stock plus the length ofthe bullet is equal to the length of the drill pin that is exposedbeyond the chuck. An illustrated embodiment of using a drill pin depthgage to set the terminal distal travel location of the drill pin isprovided in FIGS. 23A-23L, although the drawings are not to scale. Thesefigures also illustrate using a modular guide and bullet to measure abone stock and drill both a tibial and femoral tunnel in a knee. Thesurgical procedure illustrated in FIGS. 23A-23L uses both an alternativeembodiment of a drill pin depth gage, gage 480, and alternativeembodiments of a modular guide 410 and bullet 470. The features andcomponents of such devices can be similar to those described herein.Notably, although the modular guide 410 does not include a carriage andinstead the bullet 470 is mated directly to a first arm 422 of the guidearm 420 of the modular guide 410, a person having skill in the art willunderstand how guides having carriages can also be used in conjunctionwith the procedure illustrated in FIGS. 23A-23L in view of the presentdisclosure.

As shown in FIG. 23A, a modular guide 410 can be operated to set adesired location of a bone tunnel to be drilled into the tibia 1002 of aknee 1000. A trajectory for the bone tunnel can be set along the firstarm 422 using techniques described herein or otherwise known to thoseskilled in the art, and a distal tip 426 of a second arm 424 of theguide arm 420 can be positioned at a desired location for a distal endof the bone tunnel to be formed in the tibia 1002. The bullet 470 can beset in its locked position, and then can be advanced in a direction Vtowards the tibia until a distal tip 470 d of the bullet engages thebone at a desired location for a proximal end of the bone tunnel to beformed. As the bullet 470 is advanced towards the tibia, the values onthe indicia 477 formed on the shaft of the bullet 470 decrease, which issensible because the values are indicative of a thickness of the bone tobe drilled, i.e., the bone stock. The value of the indicia 477 disposedadjacent to a proximate surface 422 t of the first arm is representativeof the bone stock, as shown the distance between the distal tip 470 dand the distal tip 426. As shown in FIGS. 23A and 23B, the measured bonestock is about 45 millimeters.

The measured bone stock can be indicated on the drill pin depth gage480. As shown in FIG. 23C, an indicator 490 is locked with respect to ashaft 482 such that a proximal face 492 p of the indicator 490 islocated at the 45 millimeter mark of the indicia 486 formed on the shaft482 to indicate the maximum drill pin length. More particularly, arotatable knob 496 of the indicator 490 can be rotated to have anengagement mechanism (not shown) engage the shaft 482 and lock thelocation of the indicator 490. The knob 496 can likewise be rotated tounlock the indicator 490 and set other locations for the maximum drillpin length. The shaft 482 can be of a construction similar to the shaft382 of the drill pin depth gage 380. While the indicator 490 has adifferent locking mechanism associated with it, the indicator 490 cangenerally operate in a nature similar to the indicator 390 of the drillpin depth gage 380.

During the course of a surgical procedure, the measurement of the bonestock and respective indication of the same on the drill pin depth gagecan occur near simultaneously. For example, a surgeon or surgeon'sassistant can measure the bone stock, announce the measurement to asecond person, whether a surgeon or surgeon's assistant, who can thenset the bone stock measurement on the drill pin depth gage. This allowsfor an expedited and accurate setting of the drill pin maximum length ordistance.

FIGS. 23D-23F illustrate the insertion of a drill pin 500 into the drillpin depth gage 480. As shown, a drill pin 500 having a proximal end 500p thereof disposed within a drill chuck 502 of a drill 504 can beinserted into an elongate channel or slot 484 of the shaft 482. As shownin FIGS. 23D and 23E, the drill pin 500 can be inserted into the channel484 and placed such that its distal end 500 d engages the proximal face492 p of the indicator 492. As shown in FIGS. 23D and 23F, the chuck 502holding the proximal end 500 p of the drill pin 500 can be brought intocontact with a proximal end 482 p of the shaft 482. The chuck 502 can belocked to set the location of the drill pin 500 with respect to thechuck 502 once the distal end 500 d of the drill pin 500 is engaged withthe proximal face 492 p and a distal end 502 d of the chuck 502 isengaged with the proximal end 482 p. Accordingly, the amount of thedrill pin 500 that is exposed from the chuck 502 is equal to the lengthof the bone stock plus the length of the bullet.

After locking the drill pin 500 with respect to the chuck 502, the drill504 can be used to drill the bone tunnel, as illustrated in FIG. 23G.The resulting bone tunnel in the illustrated embodiment is actually apilot hole configured to be expanded later so it is suitable to receivethe desired ligaments therein. The drill pin 500 can be operated andpassed from the distal tip 470 d of the bullet 470 and into the tibia1002 to form a proximal end 506 p of a bone tunnel 506. The drill pin500 can then continue along the set trajectory, through the tibia 1002,to the distal tip 426 to form a distal end 506 d of the bone tunnel 506.As shown in FIG. 23H, as the distal tip 500 d of the drill pin 500 formsthe distal end 506 d of the bone tunnel 506 and reaches the tip 426, adistal portion of the drill engages the proximal face 470 f of thebullet 470, thereby preventing further advancement of the drill pin 500.This results in the configuration illustrated in FIGS. 23G and 23I, inwhich the distal tip 500 d is proximate to the tip 426. In theembodiment illustrated in FIG. 23I, the knee has been removed so theproximity of the distal tip 500 d to the tip 426 can be easily viewed. Adistance from the distal end 502 d of the chuck 502 to the distal tip500 d of the drill pin 500 can be equal to a length between the proximalface 470 f of the bullet and the terminal distal travel location.

Upon completion of the formation of the pilot hole, any number oftechniques described herein or otherwise known to those skilled in theart can be performed to expand the pilot hole into a tunnel suitable forreceiving ligament grafts therein. In one exemplary embodiment, thedrill pin 500 is part of a retrograde reamer that has an additionalcutting component or reamer 500 r (FIG. 23J) disposed proximate to thedistal tip 500 d that can be deployed outward from the shaft of thedrill pin 500 and operated to form a larger bone tunnel. Somenon-limiting exemplary embodiments of such drilling devices, andprocedures associated with using the same, are provided for in U.S.patent application Ser. No. 14/300,481, entitled “Retro-CuttingInstrument with Adjustable Limit Setting,” filed Jun. 10, 2014, thecontent of which is hereby incorporated by reference in its entirety.

Prior to performing the retrograde cut to expand the diameter of thebone tunnel, it can be advantageous to disassociate the bullet 470 fromthe modular guide 410. The guide 410 is no longer needed now that thepath for forming the initial bore has been defined and the pilot holesubsequently formed. Removing the guide 410 frees up space and hands toperform other tasks during the procedure. While many techniques can beused to disassociate the bullet 470 from the guide 410, includingtechniques described herein or otherwise known to those skilled in theart, in embodiments in which a side-loading carriage like the carriages240, 240′ are used as part of the modular guide, the bullet 470 can exitthrough the side of the carriage and the guide arm and carriage can beremoved from the surgical site. In the illustrated embodiment, nocarriage is provided, and thus the bullet 470 can be disassociated fromthe guide 410 by pulling the bullet 470 away from the tibia 1002 in adirection E until the distal tip 470 d passes the top surface 422 t. Asdescribed above, such a configuration may not be as preferable as aside-loading carriage because the drill pin 500 must be long enough toallow the bullet 470 to be disposed as described, while maintaining thedrill pin 500 in the bullet 470, thereby increasing the possibility ofdivergence.

After the bullet 470 is disassociated from the guide 410, if necessary,the bullet can be returned to a location in which the distal tip 470 dengages the tibia 1002. In some instances, the bullet may still be atthis location. This positioning allows the bullet 470 to help maintainthe trajectory for the drill pin 500 as the reamer 500 r is operated andadvanced proximally in the direction E from the distal end 506 d to theproximal end 506 p to expand the diameter of the bore 506, as shown inFIG. 23J. Once the reamer 500 r has been operated to expand the bore506, each of the drill pin 500 and bullet 470 can be removed from thelocation near the tibia 1002.

A bone tunnel 508 can likewise be formed in the femur 1004 using asimilar technique. The bone tunnel 508 that initially starts as a pilothole is illustrated in FIG. 23K. Just as with the formation of the bonetunnel 506, a modular guide can be operated to define the path for thetunnel to be formed in the femur 1004. As discussed herein, the modularguide can be similar to that used for the tibia, although typically adifferent guide arm is used because of the different location andtypical desired trajectory associated with the femur.

A bone stock for the femur 1004 can be measured, and a drill pin depthcan be set using a drill pin depth gage. A drill pin can the passedthrough the tibia to first form a proximal end 508 p of the bone tunnel508 and then form a distal end 508 d of the bone tunnel 508. Thedistance traveled by the drill pin can be limited due to the setting ofthe drill pin depth, thereby preventing unintended contact by the drillpin with tendons and other components located proximate to the distalend 508 d. The modular guide can be disassociated from a bullet in whichthe drill pin is disposed, the bullet returned to a location where itcan be used to help guide the drill pin during a retrograde procedure(if it is not already located at the desired location), and then areamer on the drill pin can be operated expand the size of the bonetunnel, resulting in the tunnel illustrated in FIG. 23L. As shown, thereamer is only operated to expand a portion of the bone tunnel 508,leaving a portion having the smaller diameter. A person having skill inthe art will recognize that a variety of other bone tunnelconfigurations are possible. As discussed herein, when a universal guidesystem like those described herein is used to form the tunnels 506 and508, a surgeon performing this procedure can use the same system withouthaving to make separate accommodations, regardless of whether thesurgeon is right hand or left handed.

One skilled in the art will appreciate further features and advantagesof the invention based on the above-described embodiments. Accordingly,the invention is not to be limited by what has been particularly shownand described, except as indicated by the appended claims. For example,to the extent the disclosures provided for herein describe devices,systems, and methods used in conjunction with ACL and PCL ligamentrepairs, a person having skill in the art would be able to apply thesedisclosures to surgical procedures performed with other ligaments, suchas the MCL, and with other anatomies and in other locations of the bodywithout departing from the spirit of the present disclosure. Allpublications and references cited herein are expressly incorporatedherein by reference in their entirety.

What is claimed is:
 1. A surgical method, comprising: setting a surgicalguide to define a path for a retrograde reamer to drill a bore in boneat a surgical site, wherein a distal tip of a bullet coupled to thesurgical guide is located proximate to a desired location for a proximalend of the bore; drilling a pilot hole in the bone along the definedpath using a drill pin end of the retrograde reamer; decoupling thebullet from the surgical guide and removing the surgical guide from thesurgical site without removing the retrograde reamer from the bullet;and operating a reamer associated with the drill pin to expand the pilothole formed in bone by advancing the reamer proximally.
 2. The method ofclaim 1, wherein the surgical guide has a carriage disposed along an armthereof, the carriage having a housing and a bullet-receiving opening,the bullet coupled to the surgical guide being disposed in thebullet-receiving opening, and wherein decoupling the bullet from thesurgical guide further comprises moving the bullet laterally, away fromand substantially perpendicular to the arm of the carriage to remove thebullet from the bullet-receiving opening.
 3. The method of claim 2,further comprising rotating the bullet in a first direction within thebullet-receiving opening to set the bullet in a locked position in whichthe bullet cannot translate away from and substantially perpendicular tothe arm of the carriage.
 4. The method of claim 3, wherein decouplingthe bullet from the surgical guide further comprises, rotating thebullet in a second direction, opposite to the first direction, such thatthe bullet is removed from the locked position and is able to be movedaway from and substantially perpendicular to the arm of the carriage. 5.The method of claim 3, wherein the bullet is configured to translatedistally, but not proximally, when disposed in the locked position. 6.The method of claim 2, further comprising locking a location of thecarriage on the arm of the surgical guide, the carriage being configuredto translate along a length of the arm to establish different angles atwhich an angle between the distal tip of the bullet and the bone can beset.
 7. The method of claim 2, wherein the carriage housing includes aproximal end and a distal end with at least one facial surface extendingtherebetween, and the bullet-receiving opening extends through theproximal and distal ends of the housing and is open towards the at leastone facial surface of the housing.
 8. The method of claim 7, furthercomprising inserting the bullet into the bullet-receiving opening of thecarriage by passing the bullet from an outside environment across aplane extending substantially through the facial surface of the carriageand into the bullet received opening.
 9. The method of claim 1, whereina length of the shaft of the retrograde reamer is approximately equal toa length of the bullet and a length of the bore drilled in bone.
 10. Asurgical method, comprising: setting a surgical guide to define a pathfor a retrograde reamer to drill a bore in bone at a surgical site;decoupling a bullet from the surgical guide and removing the surgicalguide, the bullet being configured to define a location of a proximalend of the bore to be drilled in bone, wherein the surgical guide has acarriage disposed along an arm thereof, the carriage having a housingand a bullet-receiving opening, the bullet being disposed in thebullet-receiving opening, and wherein decoupling the bullet from thesurgical guide further comprises moving the bullet laterally away from,and substantially perpendicular to, a longitudinal axis of thebullet-receiving opening of the carriage to remove the bullet from thebullet-receiving opening.
 11. The method of claim 10, further comprisingrotating the bullet in a first direction within the bullet-receivingopening to set the bullet in a locked position in which the bulletcannot translate away from, and substantially perpendicular to, thelongitudinal axis of the bullet-receiving opening of the carriage. 12.The method of claim 11, wherein decoupling the bullet from the surgicalguide further comprises, rotating the bullet in a second direction,opposite to the first direction, such that the bullet is removed fromthe locked position and is able to be moved away from, and substantiallyperpendicular to, the longitudinal axis of the bullet-receiving openingof the carriage.
 13. The method of claim 11, wherein the bullet isconfigured to translate distally, but not proximally, when disposed inthe locked position.
 14. The method of claim 10, further comprisinglocking a location of the carriage on the arm of the surgical guide, thecarriage being configured to translate along a length of the arm toestablish different angles at which an angle between the distal tip ofthe bullet and the bone can be set.
 15. The method of claim 10, whereinthe carriage housing includes a proximal end and a distal end with atleast one facial surface extending therebetween, and thebullet-receiving opening extends through the proximal and distal ends ofthe housing and is open towards the at least one facial surface of thehousing.
 16. The method of claim 15, further comprising inserting thebullet into the bullet-receiving opening of the carriage by passing thebullet from an outside environment across a plane extendingsubstantially through the facial surface of the carriage and into thebullet received opening.